Controllable growth of coral-like CuInS2 on one-dimensional SiO2 nanotube with super-hydrophilicity for enhanced photocatalytic hydrogen evolution

Abstract

Designing a semiconductor photocatalyst with a unique structure is crucial for photocatalytic hydrogen evolution. The adsorption of water molecules is considered to be an important link affecting the photocatalytic activity. Nanoconfined water molecules inside the microporous SiO2 nanotube adsorbed on the active sites boosting the photocatalytic hydrogen evolution compared with the bulk water system. Herein, hydrophilic porous SiO2 hollow nanotubes were prepared through electrospinning fiber membranes as templates. CuInS2 nanoparticles were uniformly deposited on porous SiO2 hollow nanotubes to form CuInS2/SiO2 composites. The unique CuInS2/SiO2 hollow nanotube with a coral structure was prepared. A series of characterization results show that CuInS2 supported on porous SiO2 hollow nanotubes has two advantages. On the one hand, SiO2 has excellent hydrophilicity and can be used as a micro water-collecting reactor to reduce mass transfer resistance. On the other hand, SiO2 reduces the particle size of CuInS2, thus improving the utilization rate of light, and inhibiting electron-hole recombination. The CuInS2/SiO2 with a coral structure exhibited the highest hydrogen production rate of 367.00 μmol g−1 h−1 under visible light irradiation (λ ≥ 420 nm), which is 3.1 times than that of CuInS2 powder. This work points out a novel method to enhance photocatalytic hydrogen evolution.