Chemically bonded Mn_(0.5)Cd_(0.5)S/BiOBr S-scheme photocatalyst with rich oxygen vacancies for improved photocatalytic decontamination performance

Devising exceptional S-scheme heterojunction photocatalysts utilized in annihilating pharmaceuticals and chromium contamination is significant for addressing the problem of global water pollution.In this work,a chemically bonded Mn0.5Cd_(0.5)S/BiOBr S-scheme heterostructure with oxygen vacancies is ingeniously developed through a facile in-situ solvothermal synthesis.The designed Mn0.5Cd_(0.5)S/BiOBr heterojunction exhibits eminently reinforced photo-activity for destruction of tetracycline hydrochloride and Cr(VI)as compared with its individual components.This substantial photo-redox performance amelioration is benefitted from the creation of an intense internal electric field(IEF)via supplying powerful driving force and migration highway by interfacial chemical bond to foster the S-scheme electron/hole disintegration.More intriguingly,the IEF at the hetero-interface drives the fast consumption of the photo-induced holes in Mn0.5Cd_(0.5)S by the photoelectrons from BiOBr,profoundly boosting the enrichment of active photo-carriers and sparing the photo-corrosion of Mn0.5Cd_(0.5)S.Furthermore,Mn0.5Cd_(0.5)S/BiOBr with exceptional anti-interference property can work efficiently in real water matrices.Multiple uses of the recycled Mn0⋅5Cd0⋅5S/BiOBr evidence its prominent robustness and stability.This achievement indicates the vast potential of chemically bonded S-scheme photosystems with structural defects in the design of photo-responsive materials for effective wastewater treatment.

Effects of plasticizer on removal of antibiotics and antibiotic resistance genes from agricultural soils via soil microbial fuel cells

Soil microbial fuel cells(MFCs),a novel ecosystem technology,have recently been intensively studied for antibiotic-polluted soils.However,actual agricultural soils are always contaminated by mixed pollutants,especially plasticizers from extensively used agricultural plastic films.The aim of this study was to investigate the effects of di-2-ethylhexyl phthalate(DEHP),a representative plasticizer in soil,on the removal of sulfadiazine(SDZ),a frequently detected antibiotic in natural environments,and antibiotic resistance genes(ARGs)and microbial community in soil MFCs.Soil MFCs maintained a good antibiotic removal ability even under the influence of residual DEHP and achieved a higher removal performance at higher DEHP concentrations due to enhanced power generation.Specifically,a higher DEHP concentration had a favorable effect on antibiotic removal in soil MFCs,with the SDZ concentration decreased in both the upper and lower layers(from 4.867±0.221 to 0.268±0.021 and 0.293±0.047 mg kg^(-1),respectively)of polluted soils.Moreover,a high DEHP concentration significantly promoted the abundance of bacteria associated with electricity generation compared with a lower DEHP concentration,resulting in the promotion of extracellular electron transfer and enhancing SDZ degradation.The increased ARG abundance may be caused by the enrichment of ARG potential hosts brought about by high DEHP concentration,likely due to the increased conjugative transfer frequencies of plasmid RP4 by decreasing cell membrane permeability and increasing reactive oxygen species content.The results revealed the ecological risk of residual DEHP in soil that promotes ARG transmission in soil MFCs,although it has the potential to reduce SDZ toxicity through horizontal gene transfer.We also highlight concerns regarding the management of antibiotics and plasticizers in soil.The negative effects of plasticizers on antibiotic removal should be carefully evaluated when using soil MFCs for the in-situ remediation of antibiotic-contaminated soil.

Dissolved oxygen in aeration-driven piezo-catalytic for antibiotics pollutants removal in water

The misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems.Herein,a piezoelectic odd-layered MoS_(2)is prepared and applied to piezo-catalytic remove tinidazole(TNZ)and other antibiotic pollutants with aeration as a piezo-driving force.About 89.6%of TNZ can be degraded by MoS_(2)under aeration in the presence of dissolved oxygen with a reaction rate constant of0.15 min^(-1),which is 2.4 times higher than that under N2atmosphere and quiescence conditions.Quenching experiments and electron paramagnetic resonance(EPR)tests identify that singlet oxygen(^(1)O_(2))and superoxide radical(O_(2)^(·-))are dominant reactive oxygen species in MoS_(2)/aeration system.These results demonstrate that MoS2can trigger a piezoelectric effect and produce charge carriers to generate reactive oxygen species with dissolved oxygen(DO)for contaminant degradation with the turbulence and water bubbles rupture driven by aeration.

Multi-function adsorbent-photocatalyst MXene-TiO_(2) composites for removal of enrofloxacin antibiotic from water

MXenes,a new family of two-dimensional transition metal carbides or nitrides,have attracted tremendous attention for various applications due to their unique properties such as good electrical conductivity,hydrophilicity,and ion intercalability.In this work,Ti_(3)C_(2) MXene,or MX,is converted to MX-TiO_(2) composites using a simple and rapid microwave hydrothermal treatment in HCl/NaCl mixture solution that induces formation of fine TiO_(2) particles on the MX parent structure and imparts photocatalytic activity to the resulting MX-TiO_(2) composites.The composites were used for enrofloxacin(ENR),a frequently found contaminating antibiotic,removal from water.The relative amount of the MX and TiO_(2) can be controlled by controlling the hydrothermal temperature resulting in composites with tunable adsorption/photocatalytic properties.NaCl addition was found to play important role as composites synthesized without NaCl could not adsorb enrofloxacin well.Adding NaCl into the hydrothermal treatment causes sodium ions to be simultaneously intercalated into the composite structure,improving ENR adsorption greatly from 1 to 6 mg ENR/g composite.It also slows down the MX to TiO2 conversion leading to a smaller and more uniform distribution of TiO_(2) particles on the structure.MX-TiO_(2)/NaCl composites,which have sodium intercalated in their structures,showed both higher ENR adsorption and photocatalytic activity than composites without NaCl despite the latter having higher TiO2 content.Adsorbed ENR on the composites can be efficiently degraded by free radicals generated from the photoexcited TiO2 particles,leading to high photocatalytic degradation efficiency.This demonstrates the synergetic effect between adsorption and photocatalytic degradation of the synthesized compounds.