Experimental Investigation with DFT Analysis Towards a Promising Recyclable Photocatalyst from g‐C₃N₄/ZnS Nanocomposite

Abstract

In‐situ synthesis of highly crystalline graphitic carbon nitride (g‐C3N4)/ZnS nanosphere via solution route is reported. The g‐C3N4/ZnS nanocomposite exhibited reproducible photocatalytic activity with more than 95 % degradation of Rhodamine B (RhB) under UV illumination with apparent rate constant of 0.0168 min−1, compared to pristine ZnS nanosphere which produced only 80 % degradation of RhB under the same condition. Density functional theory calculation indicated the existence of large built‐in potential (ca. 6.8 eV) at the interface of g‐C3N4/ZnS composite heterostructure that promotes effective charge transfer from ZnS to g‐C3N4 layer. The Bader charge analysis dictated a net charge transfer of 0.43e from ZnS to g‐C3N4 layer. The DFT prediction along with photoluminescent spectroscopy confirmed that improvement in photocatalytic performance of as‐prepared g‐C3N4/ZnS nanocomposite over pristine components can be ascribed to the reduction in carrier recombination followed by effective separation and transportation of charges at g‐C3N4/ZnS interface.

Experimental and first‐principles investigations on g‐C 3 N 4 /ZnS heterostructures with enhanced photocatalyst capability

“…In addition, there are few reports on the DFT theory of ZnS/g-C 3 N 4 photocatalysis. Mukherjee [18] reported the photocatalytic mechanism of ZnS/g-C 3 N 4 under ultraviolet light, which was calculated by DFT. Therefore, the theoretical research of ZnS/g-C 3 N 4 heterojunction, including work function, valence band (VB) and conductive band (CB), needs to be further explored.…”