Glyphosate is currently one of the most used organophosphorus herbicides in the world and its accumulation and translocation in soil and wave causes environmental pollution and biological health problems. A new approach to the problem is provided by the preparation of cerium and nitrogen co-doped titanium dioxide composite nano-photocatalysts loaded on modified oyster shell powder (CeNT@Oys) by a simple hydrothermal synthesis. The physicochemical and optoelectronic properties are analyzed using SEM, BET, XRD, Raman, FTIR, UV-vis DRS, XPS characterization techniques and a range of photoelectrochemical techniques. The results show that the addition of modified oyster shell powder increases its specific surface area, while Ce-N-TiO2 is an anatase crystal composed of Ce doped in the form of interstitial and surface, interstitial form of N, and the co-doping of Ce and N elements gives it the property of being excited by visible light. The photocatalytic activity of the different catalysts was evaluated by degrading 50 mg/L glyphosate solution under simulated sunlight. The catalyst was determined to be reusable by five repeated degradation experiments. Based on quenching experiments and the electron paramagnetic resonance tests, the effective active species of glyphosate degraded by the catalyst was determined and the mechanism of glyphosate degradation by photocatalyst was proposed. Finally, the degradation pathway for the photocatalytic degradation of PMG by CeNT@Oys was determined by HPLC-MS/MS determine of the intermediate products.
Modified Shell Powder/La-Fe-TiO2 (La-Fe-TiO2@MSP) composites were fabricated using the sol-gel method and characterized by SEM, XRD, UV-vis DRS and photocurrent techniques, and their physicochemical and optical properties were analyzed. The effects of various factors on the photocatalytic degradation of pyridine and its reaction kinetics were investigated by batch experiments using pyridine, a typical nitrogen-containing heterocyclic compound in coal chemical wastewater, as the target removal species. The pyridine degradation rate of 80.23% was obtained for 800 mg/L composite solution by photocatalytic oxidation of 50 mg/L pyridine wastewater for 180 min at 35 °C, pH = 8 and light intensity of 560 W. The photocatalytic degradation performance was optimal. The quenching experiments determined that the active species of photodegradation were mainly hole and hydroxyl radicals, and the photocatalytic degradation mechanism was analyzed in this way.
A new composite photocatalyst of modified oyster shell powder/Ce-N-TiO 2 was prepared by sol-gel method. Based on single factor experiment, Ce doping rate, N doping rate and calcination temperature were taken as input variables. Based on the central composite design (BBD) response surface model, two functional relationship models between three independent variables and glyphosate removal rate were established to evaluate the influence degree of independent variables and interaction on catalyst. The significance of the model and regression coefficient was tested by variance analysis. The analysis of the obtained data showed that the degradation performance of the composite photocatalyst was significantly affected by the calcination temperature and the rate of N doping, while the rate of Ce doping had little effect; at the calcination temperature of 505.440˚C, the degradation rate of glyphosate reached the maximum of 82.15% under the preparation conditions of 17.057 mol% N doping and 0.165 mol% Ce doping, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.