Au-nanorod-anchored {0 0 1} facets of Bi4Ti3O12 nanosheets for enhanced visible-light-driven photocatalysis

Abstract

Generally, plasmonic photocatalyst suffers from limited visible-light responsive and inefficient charge transfer through the noble metal/semiconductor interface, leading to unsatisfactory photocatalytic activity. To solve this problem, herein we design and prepare a high efficiency photocatalyst i.e. gold nanorods/bismuth titanate nanosheets (BTO-Au NRs), in which Au NRs selectively anchored on the active {001} facets of BTO. Upon a mild hydrothermal process, excessive organic ligands around Au NRs is removed, and as a result a clear interface forms between {001} facets of BTO NSs and Au NRs, which is beneficial to interfacial charge transfer between BTO NSs and Au NRs. The as-prepared BTO-Au NRs can harvest sunlight from visible to near-infrared light by tuning their length-to-diameter aspect ratios. The optimizing BTO-Au NRs (aspect ratios of Au NRs is 3.8) exhibits a high photocatalytic activity for the degradation of the pollutants such as α-naphthol (α-NP) and rhodamine B (RhB) under visible irradiation, with 5 and 22-fold photocatalytic efficiency with respect to BTO under the same condition, respectively. The remarkably boosted activity is demonstrated to be due to the synergetic effects of enlarged the optical adsorption range, exposed active {001} facets of BTO, as well as plasmon-induced hot electron from Au NRs transferred to the matched conduction band of {001} faceted BTO. This study offers insights into plasmonic hot electron-enabled and active facet-exposed photocatalysis, which will be valuable for the design of novel and high-efficiency plasmonic metal/semiconductor hybrid photocatalysts.