Converting Sewage Water into H 2 Fuel Gas Using Cu/CuO Nanoporous Photocatalytic Electrodes.

This work reports on H 2 fuel generation from sewage water using Cu/CuO nanoporous (NP) electrodes. This is a novel concept for converting contaminated water into H 2 fuel. The preparation of Cu/CuO NP was achieved using a simple thermal combustion process of Cu metallic foil at 550 °C for 1 h. The Cu/CuO surface consists of island-like structures, with an inter-distance of 100 nm. Each island has a highly porous surface with a pore diameter of about 250 nm. X-ray diffraction (XRD) confirmed the formation of monoclinic Cu/CuO NP material with a crystallite size of 89 nm. The prepared Cu/CuO photoelectrode was applied for H 2 generation from sewage water achieving an incident to photon conversion efficiency (IPCE) of 14.6%. Further, the effects of light intensity and wavelength on the photoelectrode performance were assessed. The current density (J ph ) value increased from 2.17 to 4.7 mA·cm -2 upon raising the light power density from 50 to 100 mW·cm -2 . Moreover, the enthalpy (ΔH*) and entropy (ΔS*) values of Cu/CuO electrode were determined as 9.519 KJ mol -1 and 180.4 JK -1 ·mol -1 , respectively. The results obtained in the present study are very promising for solving the problem of energy in far regions by converting sewage water to H 2 fuel.