Z-scheme WOx/Cu-g-CN heterojunction nanoarchitectonics with promoted charge separation and transfer towards efficient full solar-spectrum photocatalysis.

Construction of Z-scheme heterojunctions has been considered one superb method in promoting solar-assisted charge carrier separation of carbon-based materials to achieve efficient utilization of solar energy in hydrogen production and CO reduction. One interesting concept in nanofabrication that has become trend recent years is nanoarchitectonics. A heterostructure photocatalyst constructed based on the idea of nanoarchitectonics using the combination of g-CN, metal and an additional semiconducting nanocomposite is investigated in this paper. Z-scheme tungsten oxide incorporated copper modified graphitic carbon nitride (WO/Cu-g-CN) heterostructures are fabricated via immobilization of WO on Cu nanoparticles modified superior thin g-CN nanosheets. Mechano-chemical pre-reaction and a two-step high-temperature thermal polymerization process are the keys in attaining homogeneous distribution of Cu nanoparticles in g-CN nanosheets. The horizontal growth of homogeneously distributed WO nanobelts on Cu modified g-CN (Cu-g-CN) base via solvothermal synthesis is achieved. The photocatalytic performances of the heterostructures are evaluated through water splitting and CO photoreduction measurements in full solar spectrum irradiation condition. The presence of Cu nanoparticles in the composite system improves charge transport between g-CN and WO and thus enhances the photocatalytic performances (H generation and CO photoreduction) of the composite material, while the presence of WO nanocomposites enhances light absorption of the composite material in the near infrared range. The synthesized heterostructure with optimized WO to Cu-g-CN ratio and in case of no co-catalyst addition exhibits enhanced photocatalytic H evolution (4560 μmolgh) as well as excellent CO reduction rate (5.89 μmolgh for CO generation).