Au Nanorod Photosensitized La2Ti2O7 Nanosteps: Successive Surface Heterojunctions Boosting Visible to Near-Infrared Photocatalytic H2 Evolution

Abstract

Visible and near-infrared (NIR) light utilization is a high-priority target for solar-to-chemical energy conversion. In this work, a promising surface heterojunction-based plasmonic photocatalyst was developed by integrating Au nanorods (NRs) with La2Ti2O7 nanosteps (Au-LTO NSP) for photocatalytic H2 evolution in visible and near-infrared (NIR) regions. At wavelengths longer than 420 nm, Au-LTO NSP displayed H2 production rate that was separately 2.4 and 4.7 times that of Au-LTO nanosheets (NS) and Au–P25 composites, using methanol as the sacrificial agent. At wavelengths longer than 780 nm, the enhancement was 2.3 and 5.8 times, respectively. The high apparent quantum efficiency (AEQ) of 1.4% at 920 nm irradiation makes the Au-LTO NSP photocatalyst especially efficient for the NIR light utilization. The broadband photocatalytic activity of Au-LTO NSP was mainly caused by longitudinal surface plasmon resonance of Au NRs, generating and injecting hot electrons into LTO NSP. Substantial electrons transferre...