Converting Sewage Water into H2 Fuel Gas Using Cu/CuO Nanoporous Photocatalytic Electrodes

This work reports on H2 fuel generation from sewage water using Cu/CuO nanoporous
(NP) electrodes. This is a novel concept for converting contaminated water into H2 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 H2 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 (Jph) 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 (DH*) and entropy (DS*) 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 H2 fuel.