Core-shell particles of C-doped CdS and graphene: A noble metal-free approach for efficient photocatalytic H2 generation

Abstract

To achieve efficient photocatalytic H2 generation from water using earth-abundant and cost-effective materials, a simple synthesis method for carbon-doped CdS particles wrapped with graphene (C-doped CdS@G) is reported. The doping effect and the application of graphene as co-catalyst for CdS is studied for photocatalytic H2 generation. The most active sample consists of CdS and graphene (CdS-0.15G) exhibits promising photocatalytic activity, producing 3.12 mmol g−1 h−1 of H2 under simulated solar light which is ~4.6 times superior than pure CdS nanoparticles giving an apparent quantum efficiency (AQY) of 11.7%. The enhanced photocatalytic activity for H2 generation is associated to the narrowing of the bandgap, enhanced light absorption, fast interfacial charge transfer, and higher carrier density (ND) in C-doped CdS@G samples. This is achieved by C doping in CdS nanoparticles and the formation of a graphene shell over the C-doped CdS nanoparticles. After stability test, the spent catalysts sample was also characterized to investigate the nanostructure.

Keywords

• C-doped CdS@G
• Core-shell nanostructure
• Photocatalytic H2 generation
• Graphene
• Carbon doping in CdS
• Bandgap narrowing