LAUSR

Abstract Air pollution of volatile organic compounds (VOCs) threatens human health. Developing advanced photocatalysts for VOCs elimination thus attracts much interest. Bi2WO6 shows the merits of stability, nontoxicity and visible light absorbance but suffers from its rapid electron/hole recombination. Herein Ti3C2 MXene nanoparticles were electrostatically adsorbed on Bi2WO6 nanoplates for efficient electron/hole separation. Upon hybridization, electrons in Bi2WO6 flow to Ti3C2 Mxene as evidenced by XPS analysis, implying that Ti3C2 Mxene has impressive capability of trapping photoinduced electrons. As-prepared BT4 reveals increased photocurrent and weak photoluminescence under light irradiation owing to the electron-trapping effect of Ti3C2 Mxene. DFT simulations reveal that Ti3C2 Mxene has strong chemical adsorption for HCHO and CH3COCH3 for while Bi2WO6 shows weak physical adsorption. Such strong adsorption of Ti3C2 Mxene is attributed to the charge transfer between Ti3C2 Mxene and VOC molecules as disclosed by differential charge density and Bader charge analyses. The superoxide radical ( O2−) and hydroxide radical (∙OH) participated in the photo-oxidation process. As-obtained BT4 revealed 2 times and 6.6 times higher photocatalytic activity towards the degradation of HCHO and CH3COCH3 in comparison with Bi2WO6. Such superior performance of BT4 can be ascribed to favourable adsorption of VOCs and efficient electron/hole separation of Ti3C2 MXene.