Modification Of Biocl Photocatalysts And Degradation Of Rhodamine B

Water pollution caused by the excessive discharge of organic compounds is seriously endangering human health.Photocatalysis has emerged as one of the hot research areas in environmental governance in recent years due to its advantages of mild reaction conditions,green,low selectivity,low cost,and high efficiency in organic degradation.Bismuth-based photocatalytic materials have also shown great potential in the degradation of organic wastewater contamination.However,most of the existing photocatalysts are limited in various aspects,and the quantum efficiency of photocatalysts is low due to the high photoelectron-hole recombination rate,which severely limits the catalytic degradation efficiency of these photocatalysts against pollutants such as pesticide wastewater.To fully realize the potential of bismuth-based photocatalytic materials for the degradation of organic wastewater pollution,it is necessary to continue to improve the photocatalytic activity and solar energy utilization of these materials.This is also the focus of current research in the field of photocatalysis.Gray Bi OCl nanosheets with high exposure（001）,（002）,and（003）crystal faces were prepared by a simple and efficient preparation method using bismuth nitrate pentahydrate as raw material.The band gap of the prepared gray Bi OCl is reduced to 2.35 e V.The samples were characterized by X-ray diffractometer,high-resolution scanning electron microscope,transmission electron microscope,high-resolution transmission electron microscopy,X-ray photoelectron spectrometer,Fourier infrared spectroscopy,UV-Vis diffuse reflection spectrometer,and UV-Vis spectrophotometer.The photocatalytic activity of the prepared Bi OCl was evaluated by the degradation of Rh B.Moreover,it has a strong adsorption capacity and shows high photocatalytic activity for Rh B degradation under visible light.The prepared gray Bi OCl sample（0.5 g/L）can completely degrade Rh B（10mg/L）within 10 min under acidic conditions,and its visible-light catalytic activity is 80times that of commercial common Bi OCl.The photocatalytic mechanism and product of Rh B degradation by bismuth oxychloride photocatalyst was studied.The superoxide radical（·O₂^-）is the main active substance involved in the degradation of organic matter.Three kinds of Bi OCl-x photocatalysts were obtained by changing the amount of hydrochloric acid（HCl）in the process of catalyst preparation.The dominant crystal plane is（001）,and their band gap widths are reduced to 2.81 e V,2.89 e V,and 2.84 e V,respectively.The samples were characterized by X-ray diffractometer,high-resolution scanning electron microscopy,transmission electron microscopy,high-resolution transmission electron microscopy,Fourier infrared spectroscopy,UV-Vis diffraction spectrometer,and UV-Vis spectrophotometer.The degradation mechanism of Bi OCl-x on Rhodamine B has been investigated by quenching experiments on active materials.When the amount of HCl was 0.75 m L,the degradation effect of Rhodamine B was the best under the same experimental conditions（catalyst concentration 0.5 g/L）.