LAUSR

Abstract An n-p heterojunction based on ZnO/CuO supported in a zeolitic framework (ZF) was designed to produce solar fuels from H2O decomposition and CO2 conversion. ZF was synthesized from volcanic ashes by an alternative microwave-hydrothermal method using a biodegradable template for its formation. The framework resulted in NaAlSiO4 (NAS) with a high surface area and a morphology composed of circular channels of 50 nm. Incorporating the ZnO/CuO heterostructure in the NAS channels resulted in an improved light-absorption, more efficient charge transfer, nanostructure morphology, and more active sites available for the CO2 adsorption and photocatalytic reactions. The activities for H2 and light-hydrocarbons (HCOOH, HCOH, and CH3OH) evolution were evaluated in the photocatalytic water-splitting and CO2 reduction under UVA irradiation, respectively. The ZnO/CuO/NAS composite exhibited a remarkably higher H2 (187 μmol/g) and HCOOH (2721 μmol/g) evolution after 3 h of irradiation. These results were related to the synergistic effect among ZnO, CuO, and NAS framework. A mechanism of the photocatalytic reaction was proposed.