In-situ growth of CdS quantum dots on g-C3N4 nanosheets for highly efficient photocatalytic hydrogen generation under visible light irradiation

Well dispersed CdS quantum dots were successfully grown in-situ on g-C3N4 nanosheets through a solvothermal method involving dimethyl sulfoxide. The resultant CdS–C3N4 nanocomposites exhibit remarkably higher efficiency for photocatalytic hydrogen evolution under visible light irradiation as compared to pure g-C3N4. The optimal composite with 12 wt% CdS showed a hydrogen evolution rate of 4.494 mmol h−1 g−1, which is more than 115 times higher than that of pure g-C3N4. The enhanced photocatalytic activity induced by the in-situ grown CdS quantum dots is attributed to the interfacial transfer of photogenerated electrons and holes between g-C3N4 and CdS, which leads to effective charge separation on both parts.

Graphical abstractWell dispersed CdS quantum dots were grown in-situ on g-C3N4 nanosheets. The resultant CdS–C3N4 nanocomposites exhibit remarkably higher efficiency for photocatalytic hydrogen evolution under visible light irradiation as compared to pure g-C3N4. The enhanced photocatalytic activity induced by the in-situ grown CdS QDs is attributed to the interfacial transfer of photogenerated electrons and holes between g-C3N4 and CdS.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Well-dispersed CdS quantum dots are grown in-situ on g-C3N4 nanosheets. ► The CdS–C3N4 composites exhibit high H2 evolution efficiency in visible light. ► 12 wt% CdS–C3N4 shows >100 times higher efficiency than pure g-C3N4. ► Charge transfer between g-C3N4 and CdS greatly enhances charge separation.