S‐Scheme Heterojunction TiO2/CdS Nanocomposite Nanofiber as H2‐Production Photocatalyst

Abstract

One‐dimensional (1D) nanostructured photocatalyst is a promising candidate for hydrogen (H 2) generation, which can be used to deal with the energy crisis. Herein, novel 1D TiO 2/CdS well‐hybridized nanofibers (NFs) were synthesized via in situ electrospinning method. These 1D hybrid NFs showed a high H 2‐production rate of 2.32 mmol h−1 g−1 with an apparent quantum efficiency of 10.14 %, which was 35‐fold higher than that of pristine TiO 2 NFs. X‐ray photoelectron spectroscopy (XPS) analysis and density functional theory calculation implied that the electrons transferred from CdS to TiO 2 upon hybridization and created an internal electric field (IEF) pointing from CdS to TiO 2. This IEF drove the photoexcited electrons in TiO 2 to transfer toward CdS upon light irradiation as revealed by in situ irradiated XPS analysis, suggesting that a step‐scheme (S‐scheme) heterojunction was formed in the TiO 2/CdS nanohybrids and greatly promoted the separation of electron‐hole pairs to foster efficient H 2 photogeneration. The significant enhancement of photocatalytic activity was also benefited from the easy transfer for electrons in the 1D well‐distributed nanostructure of nanohybrids. This work presents a method for in situ preparing well‐distributed 1D NFs with high photocatalytic activity for H 2 production via the S‐scheme pathways.