Capture Experiments Research Articles

Targeting active sites nickel-porphyrin over BiOBr nanosheets with excellent charge separation for accelerated photoreduction reactions

The energy crisis and environmental pollution severely constrained the sustainable development of society. Herein, nickel-porphyrin active sites have been integrated over BiOBr for enhanced photocatalytic CO2 reduction and Cr(VI) removal. The optimized NiTMCPP/BiOBr-2 photocatalyst exhibits CO generation rate of 14.14 μmol g−1 under irradiation for 5h, which is around 2 times compared with BiOBr. Meanwhile, Cr(VI) removal efficiency over NiTMCPP/BiOBr-2 is 97.72% under visible light irradiation for 40min, which shows enhanced photoreduction ability compared with BiOBr (77.31%). Numerous experimental results indicate that the improved photocatalytic activity for NiTMCPP/BiOBr-2 is mainly owing to the enhanced transport efficiency of photoinduced carriers after the loading of Ni-porphyrin. Especially, the central Ni2+ active site of porphyrin can accept excitation electrons, thus enhancing photoreduction performance. Furthermore, the mechanisms for photocatalytic CO2 and Cr(Ⅵ) reduction were further discussed via in-situ FT-IR and capture experiments. This work gives a promising way to design hybrid photocatalysts for energy conversion and environmental treatment.

Efficient H2 evolution over MoS2-NiS2/g-C3N4 S-scheme photocatalyst with NiS2 as electron mediator

Low-cost transition metal sulfides are commonly utilized as photocatalysts for H2 production owing to their exceptional conductivity and superior specific surface area. In this study, MoS2-NiS2 nanoflowers with multidimensional space structure was obtained through the sulphuration reaction between S2- and NiMoO4 under Kirkendall effect during hydrothermal reaction. Subsequently, MoS2-NiS2 was loaded on the surface of g-C3N4 nanosheets using a solvent self-assembly strategy to form 3D MoS2-NiS2/g-C3N4 heterojunctions. The experimental results demonstrate that the H2 production rate of 20 wt% MoS2-NiS2/g-C3N4 reaches 22153 μmol·g-1·h-1 under a 300 W Xe lamp irradiation, which is 59.5 and 201.4-folds than MoS2-NiS2 and g-C3N4, and surpasses 20 wt% MoS2/g-C3N4 (211 μmol·g-1·h-1) and 20 wt% NiS2/g-C3N4 (6183 μmol·g-1·h-1). The XPS and Superoxide radical capture experiments demonstrate that the charge transfer between MoS2-NiS2 and g-C3N4 follows the S-scheme route, and NiS2 functions as an electron mediator, facilitating the transfer of electrons from MoS2 to g-C3N4 to consume the holes, which enhances the efficiency of H2 evolution reaction on g-C3N4. Furthermore, the S-scheme heterojunction of MoS2-NiS2/g-C3N4 with the multidimensional geometric structure can provide abundant active sites for catalytic reactions, this presents a promising approach for the development of cost-effective and high-performance g-C3N4-based heterojunctions. This work offers distinctive perspectives on the trajectory of renewable H2 energy development.

NaBiO3/g-C3N4 Z-type heterojunction modified by Ag-anchorage to enhance the photocatalytic performance

NaBiO3/Ag/g-C3N4 photocatalyst with Z-type heterostructure was developed and synthesized using photo-deposition and hydrothermal treatment methods, yielding a composite material with high REDOX ability. Because Ag in the NaBiO3/Ag/g-C3N4 composite system served as an electron capture center, the separation efficiency of photoexcited carriers was greatly increased, and the carrier lifetime was extended, as indicated by photoelectrochemical analysis. The results show that NaBiO3/Ag/g-C3N4 had much superior photocatalytic activity than monomer materials under visible light. Under visible light irradiation, the 0.1g 6% NaBiO3/Ag/g-C3N4 photocatalyst removed 95% of tetracycline in 60min. The reaction major active components were ∙O2-, ‧OH and h+, as acquired by active species capture experiments and EPR tests. Based on this, the manufacturing pathway for active compounds showed the electron transfer pathway and photocatalytic mechanism of Z-type heterojunction.

Fabrication of C and N co-doped CdS semiconductor photocatalysts derived from a novel Cd-MOF for enhancing photocatalytic performance

The narrow bandgap value and long lifetime of photo generated charges make CdS exhibit higher photocatalytic activity compared to other semiconductor catalysts. Given the excellent optoelectronic properties of CdS, a novel 2D cadmium-organic framework (Cd-MOF) was obtained by solvothermal method, which was served as a precursor template in this paper. C and N co-doped CdS-T (T = 600/800/1000) semiconductor materials were successfully prepared by chemical deposition method under different high temperatures. The as-prepared materials had been characterized in detail. Furthermore, the Cd-MOF and CdS-T were used to conduct the photocatalytic activity of organic dyes. Among them, CdS-800 showed excellent photocatalytic degradation effects on five organic dyes, especially on RB with the photocatalytic degradation efficiency of 98.87 %, which was significantly improved 6.5 times compared to Cd-MOF (58.23 %). Free radical capture experiments have shown that •O2− play a dominant role in the photocatalytic process. In addition, UV–vis diffuse reflection, photoluminescence (PL), photoelectrochemical (PEC) testing and density functional theory (DFT) calculations had shown that CdS-800 could effectively delay the recombination of photo generated charges, improve the rapid migration and separation of photo generated carriers, and enhance photocatalytic activity. This work provides new ideas for the preparation of efficient and recyclable CdS semiconductor photocatalytic materials.

Construction of Ag2Mo2O7-loaded graphdiyne S-scheme heterojunction for photocatalytically coupled peroxydisulfate-activated degradation of 2,4-dichlorophenol

The graphdiyne (GDY) used in this study was prepared by mechanochemical method, and it was loaded in situ on Ag2Mo2O7 by hydrothermal method to synthesize GDY/Ag2Mo2O7 (G/AMO), which was used for photocatalytic coupling of peroxydisulfate (PDS) activation and degradation of 2,4-dichlorophenol (2,4-DCP). When 20 mg G/AMO-2.5 was added and the concentration of PDS was 1.0 g/L, 98 % 10 mg/L 2,4-DCP could be degraded within 60 min, and the rate constant was 0.0144 min−1. The influence factor experiments showed that HCO3–, CO32– and H2PO4- favored the degradation of 2,4-DCP and that G/AMO-2.5 had good cyclic stability. According to the capture experiments as well as the ESR test results, the role of degradation actives: ·OH > h+ > SO4·-, the addition of PDS produces SO4·- under photoexcitation, which synergizes with the original ·OH and h+ in the system to further degrade 2,4-DCP. The electronic structure, theoretical bandgap and density of states of the material were calculated by density-functional theory (DFT), and the degradation mechanism was hypothesized in combination with the experimentally obtained bandgap structures: the loading of Ag2Mo2O7 on GDY formed an internal electric field, constructed an S-scheme heterojunction, and inhibited the complexation of the photogenerated charges, which improved the performance of the activated PDS in the degradation of 2,4-DCP. In this paper, a method is provided for the construction of S-scheme heterojunction photocatalysts to activate PDS to degrade pollutants.

Study on the degradation of methyl orange by UV-acetylacetone advanced oxidation system

In recent years, Acetylacetone (abbreviated as AA) has garnered considerable scientific interest, particularly in the field of dye wastewater treatment due to its distinctive enol-keto structures. In this work,degradation of methyl orange(MO) by UV/AA process was explored. Effects of AA dosage, MO concentration, initial pH value and water matrices were investigated.Experimental results showed that under conditions of 298 K, a pH of approximately 5.73, a stirring speed of 1150 rpm, an initial MO concentration of 15 mg/L and an AA dosage of 0.5 mM, the decolorization rate reached nearly 98.4 % after 12 min of photolysis. The decolorization process fitted well with the pseudo-zero-order reaction model in the UV/AA system with an R2 value greater than 0.990. The reaction rate increases as the pH decreases; at approximately pH 2.0, the decolorization rate is 99.3 % after 6 min, while at approximately pH 9.0, it is only 41.2 %. 10 mM HCO3⁻significantly inhibit the system, 0.1 mM Cl⁻has a slight promoting effect at low concentrations but inhibits at high concentrations and NO3⁻inhibits the reaction while SO42- has minimal impact at a concentration of 0.1–10 mM .0.1 mM iron ions accelerated the reaction.The sodium citrate, a printing and dyeing auxiliary, has negative impacts on the MO degradation. Free radical capture experiments and Electron Paramagnetic Resonance (EPR) tests reveal that singlet oxygen (¹O2) is the primary active species in the UV/AA system. UV-Vis absorption spectroscopy indicates that azo bonds are largely destroyed after 12 min, with a decrease in AA concentration as the reaction proceeds. Liquid chromatography-mass spectrometry (LC-MS) results suggest a possible conversion pathway for MO during the UV/AA advanced oxidation process.

Boosting the photocatalytic benzylamine oxidation and Rhodamine B degradation using Z-scheme heterojunction of NiFe2O4/rGO/Bi2WO6

The construction of heterojunction photocatalysts with powerful interfacial connections is critical for the actual utilization of photocatalytic technology. In this paper, the heterojunction photocatalyst NiFe2O4/rGO/Bi2WO6 (NFO/rGO/BWO) was prepared by in-situ hydrothermal method. Due to its excellent conductivity, rGO promoted the separation of photogenerated carriers, which was beneficial to the formation of Z-scheme heterojunction between NFO and BWO, and the absorption of visible light was improved by the involvement of rGO and NFO. Among a series of synthesized photocatalysts, 3 % NFO/rGO/BWO had the best photocatalytic activity in the photocatalytic oxidative coupling of benzylamine (BA). After 180 min of illumination, high conversion of 96 % for BA was achieved, which was 2.6 times higher than that of BWO. When it was applied to the degradation of Rhodamine B (RhB), complete degradation could be achieved, and the degradation rate was 5.67 times than that of BWO. The important roles of h+ and •O2– in the reaction were confirmed by electron spin resonance (ESR) analysis and radical capture experiments. The density functional theory (DFT) calculation and bandgap structure of the catalysts verified the existence of Z-scheme heterojunction. Potential reaction pathways for photocatalytic BA coupling and RhB degradation were proposed, respectively.

Construction of Lamellar CoFe-LDHs@MoS2 to Promote Permonosulfate Properties Leading to Effective Photocatalytic Degradation of Norfloxacin

The utilization of the photo catalytic activation of permonosulfate (PMS) for the combined breakdown of pollutants has become a focal point in research. Layered double hydroxides (LDHs) have a unique layered structure which is conducive to the adsorption and diffusion of reactants, and can provide more active sites for photocatalytic reactions. The anions between the layers can be exchanged with a variety of substances so that specific catalytically active species can be introduced as needed. LDHs themselves have certain catalytic activity, which can produce synergistic catalysis between LDHs and the supported photocatalytic active substances, and further improve the degradation effect of antibiotics. In actual wastewater treatment, LDHs as a catalyst carrier have a good application prospect. However, the poor activation effect is attributed to the low separation efficiency of catalyst carriers and insufficient active sites. In this study, a dual active site system consisting of Co and Fe, known as CoFe-LDHs@MoS2, was developed as a catalyst to facilitate the synergistic degradation of norfloxacin (NOF) by PMS under visible light. The findings demonstrate that the material possesses an effective capacity for the synergistic degradation of NOF. A comprehensive investigation was conducted to assess the impact of different catalysts, PMS dosage, degradation systems (Vis, PMS, or Vis PMS), catalyst dosage, NOF concentration, pH, and cycle times on the degradation performance. The active free radicals, degradation pathways, and intermediate toxicity were elucidated through capture experiments, Electron Paramagnetic Resonance Spectrometer (ESR) analysis, a liquid mass spectrometry (LC-MS) toxicity assessment, and theoretical calculations. This research offers a novel approach for designing catalysts with exposed high activity sites for the effective removal of NOF from environmental water.

CHARMER: detecting and harmonizing high-confidence chromatin interactions across tissues and Hi-C protocols.

Chromatin conformation capture experiments (CCC), such as Hi-C and Capture Hi-C (CHiC) work to elucidate the three-dimensional organization of the genome and the underlying epigenetic regulatory structures within. CCC experiments produce large amounts of FASTQ sequencing data with a substantial amount of technical noise and require sophisticated computational pipelines in order to extract meaningful results. Large-scale CCC data repositories like 4D Nucleome and ENCODE mostly provide raw contact information but lack annotated, statistically significant interaction data suitable for downstream genetic and genomic analyses. Here, we present CHARMER, an end-to-end pipeline integrated across multiple CCC assay types (HiC, CHiC) which generates statistically significant, harmonized, queryable, chromatin interactions in a consistent BED-like format across cell/tissue types and CCC assays. CHARMER is freely available at https://bitbucket.org/wanglab-upenn/CHARMER and harmonized chromatin interaction data will be available in the upcoming version of the FILER database ( https://lisanwanglab.org/FILER ).

In situ construction of η-Fe2O3/g-C3N4 Z-scheme heterojunction on nickel foam with efficient interfacial charge transport for enhanced photodegradation of Rhodamine B

The design of efficient, low cost and recyclable photocatalyst is of great significance for disposing organic wastewater. In this work, η-Fe2O3/g-C3N4 heterostructure was constructed by in-situ cyclic voltammetry codeposition and calcination on nickel foam (NF). The microstructural and morphological characterization of the sample confirmed that spherical η-Fe2O3/g-C3N4 nanocomposites were co-deposited on three-dimensional porous NF to form Fe2O3/g-C3N4/NF photoelectrode under 50 cycles of 50 mV/s electric field. The removal rate of as-prepared η-Fe2O3/g-C3N4/NF photoelectrode for 10 mg·L−1 Rhodamine B solution reaches 95.2 % in 1h, which is 5.6 times of g-C3N4/NF and 5.3 times of η-Fe2O3/NF, respectively. According to the electrochemical test results, the enhanced photocatalytic activity of η-Fe2O3/g-C3N4/NF was principally due to efficient photogenerated charge separation and transfer ability of the photoelectrode. The results of active species capture experiments indicate that superoxide radical, hydroxyl radical and hole almost equivalently participated in photodegradation of η-Fe2O3/g-C3N4/NF, and its possible photodegradation mechanism was proposed on the basis of Z-scheme charge transport path. The η-Fe2O3/g-C3N4/NF nanocomposites would be expected to become a promising photoelectrode for large-scale applications.

Biochar-supported Co(OH)2 nanosheets activated persulfate: Enhanced removal of ciprofloxacin and membrane purification

Developing sophisticated composite based on biochar sheds light on the breakdown of antibiotics during wastewater treatment. In this work, the new cobalt species supported on wheat biochar catalyst (Co(OH)2/biochar) nanofibers were created via a hydrothermal-electrospinning technique. A set of analyses revealed that the biochar's surface was covered by amorphous Co(OH)2 nanosheets, which had a greater capacity to activate peroxymonosulfate (PMS) and break down ciprofloxacin (CIP) compared to Co(OH)2. Specifically, the Co(OH)2/biochar/PMS system achieved 1.30 min−1 degradation rates, which is greater than pristine biochar and Co(OH)2, and the excellent PMS activation was attributed to more exposing surface Co ions and faster Co2+/Co3+ cycling. Moreover, capture experiments and X-ray Photoelectron Spectrum (XPS) of the used catalyst further confirmed that the large amount of 1O2 produced in this system stems from the synergy between the activation of PMS by Co2+ and CO of biochar. Subsequently, a self-made wastewater nanofiber purification reactor was built to drive CIP removal, and the Co(OH)2/biochar nanofiber maintained superior removal efficiency with continuous operation (8 h). Finally, the degradation pathway and toxicity estimation were further investigated. In all, this work provides a new nanofiber purification approach for the effective treatment of refractory antibiotics.

Fabrication of recoverable Bi2O2S/Bi5O7I/ZA hydrogel beads for enhanced photocatalytic Hg0 removal in the presence of H2O2

The effective removal of elemental mercury (Hg0) is a global challenge due to its toxicity and bioaccumulation threat to public health and ecosystems. Photocatalytic technology by visible light-driven photocatalysts is promising for Hg0 removal. However, effective separation of photocatalyst powders from reaction solution limits its widespread use. To solve the problem, we report for the first time the successful fabrication of recoverable Bi2O2S/Bi5O7I/ZA hydrogel beads for enhanced photocatalytic Hg0 removal in the presence of H2O2. Characterization techniques such as XRD, TEM, EDS, XPS, UV–vis DRS, PL, etc. are employed to understand the physicochemical properties and photoelectric performance of the photocatalysts. The serial BOSI photocatalysts all outperform the single component, which is attributed to the formation of a heterojunction between Bi5O7I and Bi2O2S. The coupling of 2-BOSI-ZA beads with H2O2 shows favorable synergistic effect, with Hg0 removal efficiency in the following order: H2O2 + 2-BOSI-ZA < 2-BOSI-ZA + FSL < H2O2 + 2-BOSI-ZA + FSL. TPC, EIS, and PL tests confirm that the introduction of Bi2O2S effectively suppresses charge carrier recombination. ESR and free radicals capture experiments demonstrate that the main species responsible for removal of Hg0 are •O2– and •OH. Density functional theory calculations exhibit that the internal electric field (IEF) between Bi5O7I and Bi2O2S contributes to the spatial charge separation of the heterojunction. The IEF leads to an S-scheme carrier transfer mechanism at the Bi2O2S/Bi5O7I interface that benefits the carrier separation on Bi5O7I, resulting in an enhanced photocatalytic performance. This work can provide further inspiration for designing hydrogel photocatalysts with an excellent activity in conjunction with oxidants in the field of mercury pollution control.

Construction and degradation mechanism of the magnetic CoFe1.95Y0.05O4/Ag/g-C3N4 Z-scheme heterojunction for enhanced photocatalytic activity

In this study, a Z-scheme heterojunction CoFe1.95Y0.05O4/Ag/g-C3N4 (CFYO/ACN) magnetic nanocomposite was prepared by hydrothermal synthesis. The composite was characterised and analyzed using different characterization tools and its photocatalytic degradation activity towards methylene blue (MB) was investigated. The results showed that the CFYO/ACN photocatalyst compared to CoFe1.95Y0.05O4 (CFYO) and Ag/g-C3N4 (ACN), the composite CFYO/ACN had the highest degradation efficiency of MB, which was up to 97 % within 120 min, which was 1.26 and 1.09 times higher than that of ACN and CFYO, respectively. The enhancement of the catalytic performance of CFYO/ACN was attributed to the fact that the heterogeneous junction formation effectively inhibited the complexation of photogenerated carriers. In addition, five consecutive cyclic degradation experiments showed that CFYO/ACN exhibited efficient photocatalytic degradation, stable crystal structure, and easy recycling in the photodegradation process. Finally, the capture experiments confirmed that superoxide radicals (⋅O2−) and hydroxyl radicals (·OH) play a major role in the degradation process. This study provides an effective strategy for the construction of efficient photocatalysts.

Solvothermal synthesis of a flower-like double Z-scheme PANI/Bi2Sn2O7/BiOBr/Ti photoanode and its performance in photocatalytic fuel cell

Photocatalytic fuel cell (PFC) provides a new method to degrade organic pollutants and recover their energy simultaneously. In this work, a novel flower-like hierarchical photoanode (PANI/Bi2Sn2O7/BiOBr/Ti) was synthesized by solvothermal method and assembled with Cu cathode to form a PFC for rhodamine B (RhB) degradation and simultaneous power generation. The crystal structure, chemical composition, and morphology of the photoanode was characterized by a variety of analysis techniques. The photocatalytic activity of the ternary hierarchical composite photoanode was superior to that of single and binary composite photoanodes. Its maximum photocurrent density, maximum power density, degradation rate and FF were 0.241 mA·cm−2, 21.52μW·cm−2, 92.97 % (90 min) and 0.18, respectively. In addition, it still maintains high photocatalytic activity after five consecutive uses. Based on the analysis results of transient photocurrent (i-t), EIS, DRS spectrum, M-S curve and free radical capture experiments, the improvement of photocatalytic performance of PANI/Bi2Sn2O7/BiOBr/Ti photoanode is attributed to the formation of dual Z-scheme heterojunction between PANI and BiOBr and between Bi2Sn2O7 and BiOBr, which realizes the rapid separation and transfer of electron-hole pairs, and retains the strong oxidation of holes in VB of BiOBr and the strong reduction of electrons in LUMO of PANI and CB of Bi2Sn2O7. This study provides a new research idea for the design and construction of high efficiency photoanode in PFC system.

Construction and properties of highly efficient Ag6Si2O7/C-WO3 visible light photocatalyst for water purification

Photocatalytic oxidation decomposes large molecules of organic pollutants that are difficult to biodegrade in a short period of time is a promising and effective strategy to alleviate water environmental crises. However, designing efficient, stable, and long-lasting photocatalysts remains a challenge. This article integrates C-WO3 with Ag6Si2O7 to form a Ag6Si2O7/C-WO3 heterojunction for the degradation of organic pollutants under visible light. This catalyst can capture a wider range of visible light and disperse photogenerated charges more efficiently, thus demonstrating extraordinary photocatalytic performance in photocatalytic oxidation and decomposition of large organic pollutants. After visible light irradiation for 40 min, the removal rate of organic matter reached 99.1 %, and the rate constant reached 0.0931 min−1, which is 35.1 and 13.5 times that of WO3 and C-WO3 under the same conditions. Through free radical capture experiments, it was found that h+ plays a dominant role in photocatalytic reactions. In view of the analysis of valence band positions, a reasonable photocatalytic mechanism diagram including photo generated electron transfer pathways was drawn. This undertaking affords a new idea for constructing efficient photocatalysts for water purification.

Experimental research on the bubble dynamic characteristics during carbon capture in the novel prepared functionalized porous ionic liquids

Porous ionic liquids have received widespread attention as one of the novel CO2 absorbers to reduce CO2 produced by the combustion of fossil fuels. Based on this, the CO2 capture experiments are conducted in ionic liquids ([TEP][MIm] and [TEP][FA]), and the porous ionic liquid (ZIF-8/[TEP][MIm]). The dynamic characteristics of CO2 bubbles in different concentrations of ZIF-8/[TEP][MIm] liquid are researched. The results show that the CO2 capture capacity of the aqueous solution with a concentration of [TEP][MIm] of 20 wt% reaching 2.06 mol/mol ILs. The optimal addition amount of ZIF-8 in the porous ionic liquid using the ethylene glycol as a cosolvent is 1.0 g/100 g, and the maximum CO2 capture amount is about 2.22 mol/mol. Furthermore, the aspect ratio and cross-sectional ratio of CO2 bubbles generated by the four nozzles decrease with the increase of ZIF-8 and [TEP][MIm] concentrations, and the difference between the extreme values of CO2 equivalent diameter under experimental conditions is about 0.513 cm. In addition, the Eo number decreases with the rise of CO2 bubble, and the maximum different value is about 2.94. This work explores the dynamic characteristics of CO2 bubbles in ZIF-8/[TEP][MIm] within a bubbling tower, aiming to optimize the CO2 capture process and provide a valuable reference for advancements in the carbon capture, utilization, and storage technology.

Construction of BiVO4/g-C3N4/Ag3PO4 ternary heterojunction with double Z-scheme and its photocatalytic and bacteriostatic properties

A novel Bi-composite photocatalyst BiVO4/g-C3N4/Ag3PO4 with a double Z-scheme structure was prepared by hydrothermal method assisted by honeysuckle extract. When the mass fraction of Ag3PO4 in the composite is 10 %, the inactivation rates of E.coli and S. aureus were 6.9 and 4.6 log, respectively. The MIC results were 0.6 and 0.8 mg/ml, respectively. The capture experiment confirmed that h+ and O2− were the main active substances that catalyzed bacteriostasis. Double Z heterojunction reduces the photochemical corrosion of Ag3PO4, changes the transmission path of photogenerated electrons, and then promotes the separation of photogenerated electron holes, thus obtaining significant photocatalytic activity.

Construction of GO/Pr/PbO2 ternary electrode for highly efficient degradation of organic pollutants.

A series of GO/Pr/PbO2 electrodes were prepared by an electrodeposition method, and used for electrocatalytic degradation of methylene blue (MB) in an electrolytic cell. The characteristic properties of the prepared electrodes were systematically characterized via different techniques such as XRD, SEM, and XPS. Interestingly, the ternary electrode was found to possess the higher catalytic performance compared with PbO2 and Pr/PbO2 electrodes, suggested that the synergistic catalytic activity existed between ternary electrode. Moreover, 94.64% of MB degradation was detected over the ternary electrode under the optimized conditions (50 mg/L, pH=3, 180 min). Besides, when rhodamine B, methyl orange, acid red and tetracycline were respectively used as the model pollutants, no less than 60% degradation was found. Additionally, hydroxyl radical (•OH) as reactive oxygen species was confirmed according to the free radical capture experiment, whereas, a proper degradation pathway was proposed. According to the DFT calculations, the electrons of the organic pollutants can be transferred to anode via C-O-Pr bond and Pr-O-Pb bond between dual interfaces.

Nickel-doped cuprous oxide nanocauliflowers with specific peroxidase-like activity for sensitive detection of hydrogen peroxide and uric acid

Copper-based nanomaterials have the properties of mimetic enzymes and can be used as excellent candidates for colorimetric sensing due to their environmental friendliness, low cost, and high abundance. In this paper, Ni-doped Cu2O nano cauliflower (Ni-Cu2O) was synthesized for the first time and applied to the detection of H2O2 and uric acid (UA) in human serum and urine. It was found that the proportion of Ni incorporation controls the morphology and the catalytic effect of Ni-Cu2O. The catalytic mechanism was studied by X-ray photoelectron spectroscopy, free radical capture experiments, photoluminescence spectroscopy, and steady-state kinetic analysis, which verified the redox reactions involving electron transfer and active substances. The results showed that Ni-Cu2O could catalyze the formation of reactive oxygen species (•OH, O2•−, 1O2, h+) from H2O2, which could oxidize 3,3′, 5,5′-tetramethylbenzidine (TMB) to oxTMB, and the color changed from colorless to blue. The Michaelis-Menten constant (Km) and the maximum initial velocity (Vmax) of Ni-Cu2O were 1.8 mM and 15.2×10−8 M/s, respectively. Based on the excellent peroxidase-like (POD) activity of Ni-Cu2O, a colorimetric sensing platform combined with TMB was proposed to sensitively detect H2O2 and UA in a wide range, and the detection limits were as low as 0.17 μM and 0.22 μM, respectively. This study creates a platform for using the Cu-based cauliflowers as a biosensor to detect UA in the medical and biomedicine fields.

Construction of magnetic FeP/CdS composites as photo‐Fenton‐like catalysts to realize high‐efficiency degradation of tetracycline hydrochloride

Photocatalysis is an efficient technology for the degradation of pollutants. However, it still needs to be improved. In this study, magnetic Z‐scheme FeP/CdS composites heterojunction photocatalysts were prepared by a facile hydrothermal method, and the structure, morphology, optical and photocatalytic properties of the prepared composites were investigated in detail. The efficiency of tetracycline hydrochloride (TCH) removal by FeP/CdS composites was investigated under different reaction conditions (including different FeP and CdS ratios, catalyst dosage, hydrogen peroxide consumption, temperature, and initial pH). FeP/CdS composites exhibited better catalytic performance compared with pure components. The F1Cd1 composite (mass ratio of FeP to CdS is 1:1) achieved 92.7% removal efficiency of TCH, moreover, the F1Cd1 composite still exhibits a high stability after five consecutive cycles. The capture experiments on the active material showed that the removal of TCH by the F1Cd1 composite was mainly dominated by •OH; however, •O2−, e‐, and h+ played a minor role, and the degradation mechanism was revealed by combining various characterization techniques. The introduction of cadmium sulfide formed an effective photogenerated carrier transport channel at the interface with the iron phosphide surface, which could accelerate the transfer and separation of photo‐excited e‐/h+ pairs, thus improving the degradation performance of TCH.