High efficiency p-n constructed photocatalysts based on exposed (040) crystal planes of BiVO4

Abstract

Strategy of designing new-structured semiconductor photocatalysts with great electron-hole pairs separation is meaningful for improving the photocatalytic pollution abatement. Herein, on the basis of decahedral BiVO4 with largely exposed (040) crystal facet, p-n hetero-nanostructured NiS@(040)-BiVO4 catalysts with various molar ratio of NiS were fabricated by a facile two-step hydrothermal method to study the photo-degradation activities under visible-light irradiation. To photo-degrade anion methyl orange (MO), cation rhodamine B (RhB) and tetracyclines (TC), such nanostructures can all exhibit excellent photocatalytic activities. Compared with pure (040)-BiVO4 and NiS nanoparticles, 0.6 M ratio of NiS@(040)-BiVO4 possesses 8.6, 8.9 and 6.5 times higher photocatalytic capacity (MO: 98.6%, RhB: 99.1%, TC: 98.4%) and 49.2, 64.2 and 27.7 times faster photocatalytic rate (MO: 8.4060 h−1, RhB: 8.2854 h−1, TC: 7.6230 h−1). Detailed analyses show the superior light-harvesting, higher photocurrent response, excellent charge separation and improved charge transport properties are the main factors resulting the high efficient photocatalytic performance of NiS@(040)-BiVO4 nanostructures. Besides, the forming of facet isotype heterojunctions between (040) and (220) lattice planes in BiVO4 can also help to get more active photo-induced electrons for photocatalysis.