key: cord-1018689-5gd4lkug
authors: Wu, Yadong; Li, Tao; Ren, Xulin; Fu, Yuanxiang; Zhang, Hongyan; Feng, Xiaoqing; Huang, Hongsheng; Xie, Ruishi
title: Magnetic Field Assisted α-Fe(2)O(3)/Zn(1-x)Fe(x)O Heterojunctions for Accelerating Antiviral Agents Degradation Under Visible-light
date: 2021-12-11
journal: J Environ Chem Eng
DOI: 10.1016/j.jece.2021.106990
sha: e1d9c1add7138f31ac9269df03ff91ad3df2b59d
doc_id: 1018689
cord_uid: 5gd4lkug

Reducing the recombination efficiency of photo-induced carriers has been found as an effective means to improve the degradation of antiviral agents. Given that the Lorentz forces can cause the abnormal charge to move in the opposite direction, external magnetic field improved α-Fe(2)O(3)/Zn(1-x)Fe(x)O heterojunctions (FZHx) were developed to remove increasing antiviral agents that were attributed to the COVID-19 pandemic under visible light. The characterization of the mentioned FZHx in the external magnetic field indicated that FZHx had perfect photocatalytic activity for degrading antiviral agents. In the external magnetic field, the quantities of photo-generated carriers and free radicals (•OH and •O(2)(-)) derived from FZHx increased significantly, which improved antiviral agent removal by 30.0%. Though the band structure (α-Fe(2)O(3)) is unlikely to change due to some orders of magnitude weaker of Zeeman energy in magnetic fields, which insignificantly impacts photocatalytic performance. However, this study proposed a strategy of negative magnetoresistance effects and heterojunctions to facilitate the separation and transfer of photo-induced carriers in magnetic fields. Based on the proposed strategy, spin oriented electrons were selected and accumulated on the conduction band, which contributed to the degradation of antiviral agents. Overall, this study presented novel insights into the improved degradation performance of antiviral agents by applying Fe-based heterojunctions in an external magnetic field.

The novel severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), initially discovered in December 2019, refers to a virus that has posed a global public health threat. In 2020, SARS-CoV-2 disease was termed COVID-19 (Corona Virus Disease 2019) by the World Health Organization (WHO) and caused a pandemic [1] .

On the whole, the severity of COVID-19 has been indicated in its high infectivity (e.g., directly or indirect contact with viruliferous object surfaces/waste, airborne/respiratory droplets and oral-fecal transmission) as well as the absence of a safe and effective vaccine. Compared with the mentioned severities, employing considerable antiviral agents under the COVID-19 pandemic may more severely jeopardize the natural ecosystem and human health [2] . Antiviral pollution agents fail to trigger acute intoxication, whereas its bioaccumulation and chronic toxicity caused J o u r n a l P r e -p r o o f 3 severe and irreversible harm. This threat above is inevitable to everyone, regardless of whether the demographic characteristics are. Accordingly, it is necessary to eliminate the threat of antiviral agent pollution due to COVID-19 transmission in water [3] .

Photocatalysis technology is recognized as a promising program to reduce the water pollution (e.g., antiviral agent pollution) [4] [5] . This technology is found to be more eco-friendly, sustainable, highly-efficient and low-cost. Thus, the development of new photocatalysts for improving photocatalytic performance has become a hotspot in this field. Over the past few years, most photocatalysts (e.g., TiO 2 [6] , ZnO [7] , ZnWO 4 [8] , α-Fe 2 O 3 [9] and CdS [10] ) have been modified and prepared for their prominent photocatalytic performance (e.g., catalytic degradation of a wide variety of organic dyes). To be specific, ferric oxide (α-Fe 2 O 3 ) refers to a significant photocatalyst that helps simultaneously carry out energy conversion and environmental remediation. A smaller band gap of α-Fe 2 O 3 (2.3 eV) is found to be beneficial since it can absorb visible light [11] . However, its photocatalytic activity is too poor to cope with organic pollutant. Given the mentioned facts, many references have reported the construction of heterojunction for improving the separation efficiency of photo-induced carriers and further improving photocatalytic activity. Achouri et al. reported that ZnO/Fe 2 O 3 had superior photocatalytic capabilities to commercial ZnO due to the effective electron/hole separation at the ZnO/Fe 2 O 3 heterostructures [12] . According to Liu et al., the ZnO/Fe 2 O 3 NT composites exhibited high excellent photocatalytic activity for methylene blue degradation [13] . As reported by Hashim for about 200 min [14] . As indicated by Li et al., Cu-Fe 2 O 3 /Ni-ZnO nanoplate photocatalysts were prepared and they showed high photocatalytic performance [15] . J o u r n a l P r e -p r o o f 4 Tang et al. reported the synthesis of α-Fe 2 O 3 /TiO 2 composite hollow microspheres through a template-assisted precipitation reaction. Though energygap has been well adjusted, the separation efficiency of carrier remains lower than the expected value [16] . Furthermore, the mentioned reports largely focused on the degradation of organic dyes and did not practically applied the composites in sewage.

Recently, the stimulation of magnetic fields on photocatalytic activity has aroused extensive attention, and practical applications have been conducted in some related catalysis fields [17] [18] [19] . For instance, non-redox, Diels-Alder reaction's bond-formation can facilitate the movement of carriers by the Lorentz forces.

Magnetic field assisted ferromagnetic photocatalyst (e.g., α-Fe 2 O 3 ) has been widely reported to accelerate organic dye degradation. However, the band structure (α-Fe 2 O 3 )

is unlikely to change due to some orders of magnitude weaker of Zeeman energy in magnetic fields, thereby causing a limited effect on photocatalytic performance. Accordingly, plentiful researches proposed the strategy of negative magnetoresistance effects to facilitate separation and transfer of photo-induced carriers in magnetic fields.

Wang et al. reported the successful synthesis of α-Fe 2 O 3 /reduced graphene oxide (rGO) through the hydrothermal process, and the photocatalytic efficiency was improved in the magnetic field. Their study found that the synergistic effect of electron acceptor/transporter materials (rGO) and magnetic-field-reduction could be more conducive to the optimization of its photocatalytic performance than pure α-Fe 2 O 3 [20] . Moreover, Huízar-Félix et al. employed reduced rGO decorated with α-Fe 2 O 3 nanoparticles to remove tetracycline pollutants through adsorption and magnetic separation. As revealed by their study, the rGO/α-Fe 2 O 3 nanometer materials exhibited the ferromagnetic character formed by separation in an external magnetic-field [21] . 

X-ray diffraction (XRD) patterns were recorded on a PANalytical X'Pert PRO with Cu Kα radiation (λ=1.5406 Å, at 40 kV and 40 mA). A Carl Zeiss Ultra 55 was used for scanning electron microscopy (SEM). X-ray photoelectron spectroscopy (XPS) analyses were conducted by applying a Thermo Fisher Scientific K-Alpha.

Transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) were conducted with a Carl Zeiss LIBRA 200FE. A Shimadzu SolidSpec-3700 was adopted to record Ultraviolet-visible (UV-vis) spectra. Vibrating sample magnetometer (VSM) patterns were recorded on America LakeShore Company.

Fluorescence spectrophotometer (PL) spectra were recorded with a F-4600, Shanghai

Devos. Electrochemical workstation measurements were recorded on a Shanghai Chenhua CHI760E. Electron paramagnetic resonance spectrometer (EPR) were tested by German bruck A300. Total organic carbon analyzer (TOC) was tested by Shimazu TOC-V WP. all samples were ultrasonicated for ~50 min to achieve an equilibrium of dispersion and adsorption, and subsequently kept in the dark for ~20 min to achieve an equilibrium on the surface of the photocatalysts. Next, a Xe lamp was placed ~5 cm above the beaker, and ten fixed permanent magnets (20 mT) were set on both sides.

During the photoreactions, ~3 mL of the antiviral agent supernatant liquid was sampled per 10 min and then tested at 206, 228, 257 nm. Next, the photocatalytic experiment of αF and FZHx was repeated in the absence of the external magnetic field. Eq. (1) was adopted to determine the degradation rate:

Where C 0 and C t (mg L -1 ) respectively denote the initial and post-degradation concentrations of the aqueous antibiotic solutions. [25] was smaller than that of Zn 2+ (0.74 Å) [26] .

Besides, the distance between crystal decreased, and the samples of the in situ doping of Fe 3+ into the ZnO lattice and synthesis of FZHx were found to be feasible. Fig. 3 presents the SEM images of αF and FZH3. αF presents regular particles, consistent with a tablet-like morphology with a thickness of ~10-15 nm and diameter of ~60-100 nm (Fig. 3a) . The samples of FZH3 showed almost multangular particles, with the average sizes ~<125 nm. Moreover, the number of edges decreased as the doping concentration of Fe 3+ increased and the amount of αF increased. Considerable tablet-like αF was tightly inserted on the surfaces of ZFx, which indicated that the heterojunctions of αF and ZFx were obtained in the one-step hydrothermal process.

This scaly structure was considered to achieve a larger specific surface area and more active sites. The particle size tended to decrease with value of Fe augmentation, which was consistent with the foregoing XRD analysis. The sample of FZH3 was a spheroid (Fig. 3d) . As indicated by the EDX spectra in Fig. S1 , FZH3 sample was composed of Zn, O and Fe, and all the elements were evenly distributed in FZH3. To further observe the specific particle elemental distribution, a specific particle was analyzed on the EDX, which exhibited a ellipsoid structure. FZH3 achieved a high-concentration of Zn, O and Fe elements in this particle (Fig. 4 a-c) . As indicated by Fig. S2 and Table 1 , the ratio of elements was consistent with synthetic raw materials (FZH3). The first peripheral core achieved slightly lower concentrations of Fe and O than the core.

The change of the concentration of ions, including a sharp drop in the reaction of Zn 2+ , Fe 3+ and OH -, had a radical effect to reduce the elemental density in the first J o u r n a l P r e -p r o o f 11 peripheral core. Next, the second core periphery contained slightly higher concentrations of Zn, O, and Fe than the first one. The element distribution of Fe and Zn in the second core periphery was greater than that of the first one due to the increase in the concentration of OH -. Notably, the elements of core periphery turned out to be thinner gradually due to a gradual decrease in the concentration of Zn and Fe in the cyclical process. The FZHx ellipsoidal structure above might be correlated with solubility product rules and precipitation conversion. The specific computational process of solubility product rules could be compared with the ion product (Q) and solubility product constant (K SP θ ). Fig. 4d presents the formation of FZHx composite material. According to the literature, the solubility product constants of Zn(OH) 2 and Fe(OH) 3 were determined as 6.8 × 10 -17 [27] and 2.8 × 10 -39 [28] , respectively.

(3)

Given the EDX spectra in Fig. 4a , high-concentrations of Zn, O and Fe in the core were explained by Eqs. (3-6).

J o u r n a l P r e -p r o o f 12 (10) According to the EDX spectra in Fig. 4b , the first core periphery containing slightly lower concentrations of Fe and O than the core were expressed by Eqs. (8-9) and (7, 10) . When the Fe(OH) 3 could produce precipitation other than Zn(OH) 2 . In addition, the K was excessive large, which revealed that Zn(OH) 2 could be converted into Fe(OH) 3. After recycling, FZHx were prepared. Lastly, the tablet-like αF was tightly embedded on the surfaces of ZFx due to Eq. 10.

The morphological characteristics exhibited by FZH3 were characterized with bright-field TEM, high-resolution TEM (HRTEM), and selected area electron diffraction (SAED) and dark-field TEM. According to Fig. 5a , the sample of FZH3 exhibited an almost ellipsoidal structure, in which the long axis was ~50-250 nm and the short axis was ~35-90 nm. The HRTEM image indicated that FZH3 was highly crystallized (Fig. 5b) . Furthermore, the lattice spacings of d = 0.260, 0.281 and 0.248 nm belonged to the (002), (100), and (101) crystal faces, respectively. Fig. 5c presents the SAED image of FZH3 and diffraction rings corresponding to the FZHx phase. Fig.   5d illustrates the dark field micrograph by setting a Z (101) ring of ZFx on the SAED image. The main body of the ZFx layer (the last peripheral core) was the brighter region, and the samples of αFe were the brighter scales. As indicated by the XRD and EDX results, the conclusions above confirmed that FZHx were successfully prepared with the mentioned method. 

Since the FZHx photocatalysts were synthesized through the hydrothermal process, whether the photocatalysts exhibited better photocatalyst properties was also investigated. Ribavirin, Chloroquine Phosphate and Arbidol were adopted to represent antiviral pollution agents in water to assess the photocatalytic activity of αF and series of FZHx. The overall antiviral pollution agents in water were self-degraded by <1% before the simulated sunlight irradiation.

According to Figs. 7a and 7c, the adsorption of Ribavirin pollutant was lower than 25% in the dark under external (or without) magnetic field exposure. However, the adsorption capacity of samples (in the magnetic field) was significantly better than that of another group (in the absence of the magnetic field). This result was achieved because Lorentz force could facilitate the adsorption performance in external magnetic fields. Furthermore, FZHx disposed by an external magnetic field achieved the highest photocatalytic activity during the photocatalytic degradation. The optimal degradation rate of αF and FZHx at the highest concentration (50 mL 30 mg L -1 Ribavirin) was 46% after ~50 min in a magnetic field, which was significantly better than in the absence of a magnetic field. According to Fig. 7c , the degradation of Ribavirin when treated with αF and FZHx in a magnetic field fitted a pseudo-first-order kinetics model. The linear relationship of ln(C t /C 0 ) versus time was J o u r n a l P r e -p r o o f 15 determined by ln(C t /C 0 ) = kt. Furthermore, its degradation constants (k) reached 0.0078 (αF), 0.0125 (FZH1), 0.0178 (FZH2), and 0.0188 (FZH3) min -1 (Fig. 8d) , respectively, which confirmed that the photocatalytic properties of Ribavirin in a magnetic field were 1.5 times that in the absence of a magnetic field. According to the TOC results, it is can be seen that the TC are mineralized into carbon dioxide and water (Fig. S3) . To reveal the degradation of other antiviral pollution agents, the highest concentrations of Chloroquine Phosphate (50 mL 10 mg L -1 ) and Arbidol (50 mL 30 mg L -1 ) were examined under the exposure of an external (or without) magnetic field ( Fig. S4 and Fig. S5 ). It was obvious that the degradation results of Chloroquine Phosphate and Arbidol were consistent with the removal of Ribavirin.

According to Table 2 , the photocatalytic degradation of all antiviral pollution agents exhibited advantageous performance in the magnetic field. In particular, the degradation of Arbidol was the most significant. Truism, a product of more free radicals, was critical to the photocatalytic degradation. It could be estimated that the production of free radicals increased by 30% in an external magnetic field. According to the table 3, our design is better than that of the previous products. On the one hand, the negative reluctance effect of αF and FZHx was regarded as a vital factor to determine the catalytic performance. And the error bars of photocatalytic degradation for antiviral agent have been shown in the Fig. S6 . From the picture, we could find that the samples (αF and FZHx) of are relatively stable. On the other hand, the photocatalyst of FZH3 was regarded as relatively stable according to Fig. S7a and Fig.   S7b . The Fig. S8 is shown that the standard deviation of FZH3 photocatalytic cyclic J o u r n a l P r e -p r o o f 16 experiment for Chloroquine Phosphate is no more than 0.05. Therefore, the data of cyclic degradation generally tended to be stable.

To further evaluate the light absorption properties, the UV-vis adsorption spectra and band gaps of αF and FZHx were obtained, and the samples were scanned to show the wavelengths in the 800-200 nm range. According to the UV-vis DRS spectra (Fig.   8a) , αF was clear in the visible region, which was consistent with several studies. In addition, the absorbance of FZHx was prominently extended into the visible region with the augmentation of Fe. The band gap of the samples was changed by iron incorporation and the construction of heterojunctions, which could be the key factor of the red-shift trend. Eq. 11 was adopted to estimate the band gap energy of the samples [31] : (11) where C denotes a constant; h is the Planck constant; ν is the incident photon frequency; α is the absorption coefficient; E g represents the band gap energy. (Fig. 9b) . The phenomenon above was explained by the following factors: 1) the structural defects caused Fe 3+ to merge with ZFx, which acted as the trapping centers for photogenerated electrons and contributed to reconcile carrier separation [32] ; 2) the interfacial interactions between αF and ZFx due to ohmic contact improved the separation and transfer efficiency of photo-generated carriers in the absence of a magnetic field [33] ;. 3) the photo-induced electrons in the conduction band (CB) of ZFx could shift to the VB of αF, thereby restraining the recombination of electrons and holes (ZFx); 4) αF, belonging to ferromagnetic semiconductor, showed a typical spintronic phenomenon, which revealed that the resistance could be reduced under a magnetic field (negative MR effect) [34] . To extensively discuss the effect of photoelectric properties under magnetic conditions, the sample was characterized by chronoamperometry and electrochemical impedance spectroscopy (EIS). As expected, photocurrent responses were provided in the presence and absence of a magnetic field, peaking at 0.75 and 0.55 μA cm -2 , respectively, for FZH3 (Fig. 9c) . EIS indicated that the sample of FZH3 in the magnetic field conditions had a smaller arc radius in the Nyquist plot than without magnetic field (Fig. 9d) . This result demonstrated that the J o u r n a l P r e -p r o o f 18 separation efficiency of photogenerated carriers was improved, which was due to the lowest impedance of charge transfer. Thus, the separation efficiency of photogenerated electron-hole pairs obviously increased on FZH3 due to negative reluctance effect and heterojunction. The result above was consistent with the photocatalytic degradation of antiviral pollution agents under magnetic conditions. In general, the higher recombination rates of photo-induced electrons and holes were adverse to photocatalytic performance. However, this study was different from the previous theory. The separation capability of photogenic charge carriers was assessed by the photoluminescence (PL) under (or without) a magnetic field. All samples (FZHx) showed similar and asymmetrical emission peaks at approximately 604 nm (Fig. 10a) . Furthermore, the emission intensity of FZHx clearly decreased as the value of Fe decreased. High recombination rates of photogenerated electrons and holes revealed that the samples had high PL intensities. However, photo-induced electrons of Zn 1-x Fe x O (ZFx) might be captured by the CB of αF, which demonstrated that the recombination of photo-induced electrons (e -) and holes (h + ) (ZFx) could be effectively inhibited. In other words, the conduction bands of ZFx and αF consisted of the new band gap that effectively stopped the recombination of photogenic charge carriers of FZH3, which was assessed with and without magnetic field exposure to determine emission intensity (Fig. 10b) . The emission intensity of the same sample was clearly higher under magnetic conditions than that without magnetic conditions.

The sample of αF have higher PLdensity under magnetic field (Fig.10c) . According to Accordingly, the separation efficiency of photogenerated electron-hole pairs (the CB and VB of ZFx) obviously increased, thereby inhibiting the recombination of the sample in the magnetic field. In addition, the emission intensity of αF was higher with magnetic field than without it. This study inferred that when the external magnetic field was applied at the beginning (i.e., instantaneous magnetic field), the photogenerated carriers shifted due to the Lorentz force on αF (Hall effect was generated later than the Lorentz force), thereby increasing the transitory carrier recombination rate.

To determine the high photocatalytic efficiency for the degradation of antiviral pollution agents in the magnetic field, the photocatalysts of FZHx were investigated (Fig. 11) . A typical saturation magnetization (M-H curve) with high coercivity of αF was identified and saturated under a magnetic field of 20 KOe. It was found that the ferromagnetic αF had lower residual magnetization [35] [36] [37] . In addition, the 

To analyze the photocatalytic mechanism in depth, the free radical capture of FZH3 was used in the photocatalytic degradation for aqueous Arbidol (30 mg/L, catalyst dose = 0.1 g, pH = 7.0) in the visible light. On the whole, high selectivity of free radical can be adopted assess photocatalytic processes. AgNO 3 , p-Benzoquinone, 2-Propanol and (NH 4 ) 2 C 2 O 4 , are common capture agents since they are capable of capturing the free radicals of photogenerated electrons (e − ), *O 2 , *OH and photogenerated holes (h + ), respectively [38] . According to Fig. 12 , the degradation rates of FZH3 using different capture agents were AgNO 3 (74.9 %), p−Benzoquinone (32.4 %), 2−Propanol (22.2 %), (NH 4 ) 2 C 2 O 4 (27.0 %), respectively. In addition, the mechanism can be aquired by ESR and terephthalic acid photoluminescence analyses [39] [40] [41] . According to the Fig. S9 , the obtained ESR and TA-PL results were also in good agreement with the outcomes of radical trapping tests, which strongly authenticated the production of •OH and O 2 •radicals during the photocatalytic process. The free radicals of *OH *O 2 and h + were the main active species in the free radical capture experiment. Thus, e − and *O 2 were found as the free radicals capable of degrading aqueousArbidol, which was obviously weaker than the degradation abilities of e -.

Given the above mentioned results, the possible photocatalytic mechanism was proposed ( Fig. 13 ). FZH3 could produce more photo-generated carriers in a magnetic field (Eq. 12). (↑ represents augmentation, ↓ represents reduction) Under magnetic-field:

Without magnetic field: Indeed, some side effects might be exerted in the process above, including *HO 2 (Eq. 19 ), H 2 O 2 (Eq. 20) and *OH (Eq. 21). Ultimately, the remaining and few photon-generated carriers were recombined, and more energy was released. In conclusion, the separation efficiency of photogenerated electron-hole pairs clearly increase, inhibiting the recombination rate of the sample under the external magnetic field and further improving the quantity of free radicals. Therefore, this dynamic cycle of degrading antiviral pollution agents is proposed.

In summary, the samples of FZHx were triumphantly fabricated by the one-step 

The Importance of

Continuing Breastfeeding during Coronavirus Disease-2019: In Support of the World Health Organization Statement on Breastfeeding during the Pandemic

A novel and stable way for energy harvesting from Bi2Te3Se alloy based semitransparent photo-thermoelectric module

Synthesis of hierarchical hetero-composite of graphene foam/α-Fe 2 O 3 nanowires and its application on glucose biosensors

Emerging pollutants and their removal using visible-light responsive photocatalysis-A comprehensive review

Nanometric and surface properties of semiconductors correlated to photocatalysis and photoelectrocatalysis applied to organic pollutants -A review

Mechanism of photodegradation of organic pollutants in weawater by TiO 2 -based photocatalysts and improvement in their performance

Hybrid PVDF-P(L-DOPA)-ZnO membranes for dyes and antibiotics removal through simultaneous action of adsorption and photocatalysis processes

Rodlike Cadmium-incorporated zinc tungstate nanoarchitecture fabricated by a facile and template-free strategy as a photocatalyst for the effective degradation of organic pollutants in sewage

Preparation of

Si-α-Fe 2 O 3 /CdS composites with enhanced visible-light photocatalytic activity for p-nitrophenol degradation

H 2 O 2 treated CdS with enhanced activity and improved stability by a weak negative bias for CO 2 photoelectrocatalytic reduction

The role of cobalt phosphate in enhancing the photocatalytic activity of α-Fe 2 O 3 toward water oxidation

Aqueous synthesis and enhanced photocatalytic activity of ZnO/Fe 2 O 3 heterostructures

Preparation and photocatalytic activity of ZnO/Fe 2 O 3 nanotube composites

Photocatalytic degradation of GRL dye from aqueous solutions in the presence of

ZnO/Fe 2 O 3 nanocomposites

Engineering the band-edge of Fe 2 O 3 /ZnO nanoplates via separate dual cation incorporation for efficient photocatalytic performance

Hydrothermal synthesis and visible-light photocatalytic activity of α-Fe 2 O 3 /TiO 2 composite hollow microspheres

Designing of TiO 2 /α-Fe 2 O 3 coupled g-C 3 N 4 magnetic heterostructure composite for efficient Z-scheme photo-degradation process under visible light exposures

Facile fabrication of magnetically recyclable Fe 3 O 4 /BiVO 4 /CuS heterojunction photocatalyst for boosting

simultaneous Cr(VI) reduction and methylene blue degradation under visible light

Enhanced photocatalytic performance through magnetic field boosting carrier transport

A α-Fe 2 O 3 /rGO magnetic photocatalyst: enhanced photocatalytic performance regulated by magnetic field

Removal of tetracycline pollutants by adsorption and magnetic separation using reduced graphene oxide decorated with α-Fe₂O₃ nanoparticles

Selective hydrogenolysis of xylitol to ethylene glycol and propylene glycol over copper catalysts

Synthesis and characterization of zirconium-doped mesoporous nano-crystalline TiO 2

Effect of Ai 3+ introduction into hydrothermally prepared ZnFe 2 O 4

Nano-ZnO Composites

Reduction of Fe(III) (Hydr)oxides with known thermodynamic stability by geobacter metallireducens

Competitive mechanism and influencing factors for the simultaneous removal of Cr(III) and Zn(II) in acidic aqueous solutions using steel slag: batch and column experiments

Synthesis and Gas Sensing Properties of α-Fe 2 O 3 @ZnO Core-Shell Nanospindles

Understanding Lanthanum Oxide Surface Structure by DFT Simulation of Oxygen 1s Calibrated Binding Energy in XPS After in Situ Treatment

Multi-shelled ZnO decorated with nitrogen and phosphorus Co-doped carbon quantum dots: synthesis and enhanced photodegradation activity of methylene blue in aqueous solutions

Engineering of oxygen vacancy as defect sites in silicates for removal of pollutants and enhanced aromatic alcohol oxidation

Ohmic contacts simultaneously formed on n-type and p-type 4H-SiC at low temperature

Multi-shelled ZnO decorated with nitrogen and phosphorus Co-doped carbon quantum dots: synthesis and enhanced photodegradation activity of Methylene Blue in aqueous solutions

Harnessing the biomedical properties of ferromagnetic α-Fe 2 O 3 NPs with a plausible formation mechanism

Room-temperature weak ferromagnetism induced by point defects in α-Fe 2 O 3

Band gap tuning, n-type to p-type transition and ferrimagnetic properties of Mg doped α-Fe 2 O 3 nanostructured thin films

Synthesis of LAS/ZnO/ZnWO 4 3D rod-like heterojunctions with efficient Photocatalytic performance: Synergistic effects of highly active site exposure and low carrier recombination

Magnetic NiFe 2 O 4 nanoparticles decorated on N-doped BiOBr nanosheets for expeditious visible light photocatalytic phenol degradation and hexavalent chromium reduction via a Z-scheme heterojunction mechanism

Abdul Rahman MohamedInsight into the influence of noble metal decorated on BiFeO 3 for 2,4-dichlorophenol and real herbicide wastewater treatment under visible light

An overview of subcritical and supercritical water treatment of different biomasses for protein and amino acids production and recovery

Visible-light-driven photocatalytic disinfection of human adenovirus by a novel heterostructure of oxygen-doped graphitic carbon nitride and hydrothermal carbonation carbon

Nath， Multi-core-shell composite SnO 2

NPs@ZIF-8: potential antiviral agent and effective photocatalyst for waste-water treatment

Application of phosphorescent material in activation of N:Cu:TiO 2 photocatalyst as antibacterial and dye removal agent from solid surfaces used in hospitals

Hongsheng Huang: Experimental design and hardware support

Writing-Original draft preparation and sample preparation Tao Li: Sample characterization Xulin Ren: Sample characterization

Analyze data Hongyan Zhang: Find literature Xiaoqing Feng: Check format