Solvothermal synthesis of metallic 1T-WS2: A supporting co-catalyst on carbon nitride nanosheets toward photocatalytic hydrogen evolution

To date, despite significant achievements in noble-metal co-catalysts, it is still challenging to develop highperformance noble-metal-alternative co-catalysts for economic hydrogen production. In this work, we demonstrate that the metallic 1T-WS2 obtained through a facile solvothermal method can function as co-catalyst for boosting the photocatalytic hydrogen production with the merits below: (i) noble-metal-free; (ii) excellent electrical conductivity; (iii) extra active sites on basal plane rather than edge sites for H-2 generation. As demonstrated in photocatalytic hydrogen evolution, the designed composite using two-dimensional carbon nitride (2D-C3N4) as semiconductor and 1T-WS2 as co-catalyst (1T-WS2/2D-C3N4) exhibits giant enhancement, in comparison with the bare 2D-C3N4 and 2H-WS2/2D-C3N4. This work highlights the surface engineering strategy of co-catalysts such as phase engineering for promoting the photocatalytic performance.