SOLUTION PROCESSED SB2S3-BASED PHOTOCATHODE WITH ENHANCED PHOTOCATALYTIC PERFORMANCE VIA CONSTRUCTING ULTRATHIN TIO2 OVERLAYER AND NOBLE METAL MODIFICATION

Antimony sulfide (Sb2S3) is a light absorbing material with strong visible light response, which is suitable for efficient and low-cost photoelectrodes. Nano-structured films have unique advantages in constructing photoelectrodes due to the enhanced light absorption and carrier migration. However, on account of low carrier concentration and carrier diffusion length(30-300nm) of Sb2S3, finding an effective and low-cost way to grow a unifirmly-coated ultrathin overlayer on three-dimensional Sb2S3 film to deepen the space charge rigion into interior of Sb2S3 is the key to improve carrier utilization, and is significant to constructing a low-cost photocathode with high efficiency. In this work, we report a Sb2S3-based heterostructure photocathode using nanostructured Sb2S3 as light absorption layer. After coated with ultrathin TiO2 layer with a simple electrodeposition method and modified with Pt particles, the Sb2S3-based photocathode achieves a photocurrent density of 2.7 mA/cm2 at 0 VRHE in a near-neutral electrolyte, about twelve times higher than pure Sb2S3, with an onset potential of +0.55 VRHE. The maximum IPCE of Sb2S3-based photocathode reaches 17.5% at 700nm. Our experimental result confirmed Sb2S3’s promising application as a light absorbing material for photocatalysis, and put forward a facile and effective way to coat ultrathin TiO2 on 3D nanostructured films, which will promote further investigation of nano Sb2S3-based photocathodes.