Enhanced visible light photocatalytic H2 evolution of metal-free g-C3N4/SiC heterostructured photocatalysts

g-C3N4 has been attracting much attention for application in visible light photocatalytic water splitting due to its suitable band structure, and high thermal and chemical stability. However, the rapid recombination of photogenerated carriers has inhibited its wide use. For this reason, novel g-C3N4/SiC composites were prepared via in situ synthesis of g-C3N4 on the surface of SiC, with which g-C3N4 shows tight interaction (chemical bonding). The g-C3N4/SiC composites exhibit high stability in H-2 production under irradiation with visible light (lambda >= 420 nm), demonstrating a maximum of 182 mu mol g(-1) h(-1), being 3.4 times higher than that of pure g-C3N4. The enhanced photocatalytic H-2 production ability for g-C3N4/SiC photocatalysts is primarily ascribed to the combined effects of enhanced separation of photogenerated carriers through efficient migration of electron and enlarged surface areas, in addition to the possible contributions of increased hydrophilicity of SiC and polymerization degree of g-C3N4. This study may provide new insights into the development of g-C3N4-based composites as stable and efficient photocatalysts for H-2 production from water splitting. (C) 2016 Published by Elsevier B.V.