Insights into the function of semi-metallic 1T’ phase ReS2 as cocatalyst decorated g-C3N4 nanotubes for enhanced photocatalytic hydrogen production activity

Abstract

In this paper, the semi-metallic 1T’ phase rhenium disulfide (ReS2) nanosheets (NSs) as cocatalysts are loading on the graphitic carbon nitride (g-C3N4) nanotubes (NTs) for photocatalytic hydrogen (H2) production. The as-prepared 1T′-ReS2/g-C3N4 composites present expressively enhanced photocatalytic activity. The 1T′-ReS2/g-C3N4 composite with 12 wt% 1T′-ReS2 exhibits the best photocatalytic H2 evolution performance (2275 μmol h−1 g−1), about 37 times of g-C3N4 NTs, 4 times of 2H-ReS2/g-C3N4 NTs, 6.7 times of 1T-ReS2/g-C3N4 NTs and 1.2 times of Pt/g-C3N4 NTs. Meanwhile, the apparent quantum yield (AQE) values of 1T′-ReS2/g-C3N4 (12 wt%) using 50 mg photocatalyst are 6.44% and 3.45% under light at λ = 370 nm and 456 nm, respectively. The activity tests and the DFT calculations prove that 1T′-ReS2/g-C3N4 composites have the following advantages: 1) The hollow porous g-C3N4 nanotubes are beneficial for improving the absorption and utilization of light, and the migration of photoexcited electrons; 2) After loading 1T′-ReS2 nanosheets on the g-C3N4 nanotubes, the 1T′-ReS2/g-C3N4 composites show the enhanced light absorption and fast carriers transfer, proving that the conductive 1T′-ReS2 nanosheets as cocatalysts could facilitate g-C3N4 nanotubes to generate more photoexcited charges, promote the carrier migration and separation, and supply abundant active sites for photocatalysis.