Cu2O as an emerging photocathode for solar water splitting - A status review

Modification of large area Cu2O/CuO photocathode with CuS non-noble catalyst for improved photocurrent and stability

“…It is also worth to notice that, in the case of Cu 2 O, the majority of the current recorded was correlated to the reduction of the semiconductor material to the metallic state (Cu 2 O → Cu), sustaining the photocurrent densities at a high cathodic bias (< 0 V vs RHE). The energy level of the self-reduction reaction lies indeed between the conduction band and the hydrogen evolution energy level, favoring the degradation reaction rather than the proton reduction 3 . However, the dark current of the Cu 2 O/CuO photoelectrode was different from zero, especially approaching 0 V versus RHE, suggesting either a sign of catalytic activity of the overlayer or the presence of a secondary reaction such as self-reduction.…”

“…Cuprous oxide (Cu 2 O) is one of the most investigated p-type semiconductor material in the framework of photoelectrochemical hydrogen production 1 – 3 , mainly because of its optical properties and potentially low-cost synthesis 4 . It has indeed a direct bandgap of ~ 2.1 eV, capable to absorb a large part of the solar spectrum, resulting in a theoretical maximum photocurrent density of − 14.7 mA cm −2 at AM 1.5 G condition 4 , and has a favorable conduction band position with respect to the hydrogen evolution reaction potential.…”

Achieving visible light-driven hydrogen evolution at positive bias with a hybrid copper–iron oxide|TiO2-cobaloxime photocathode

“…The instability of semiconductors under photoelectrochemical conditions is a general problem that can be solved by deposition of metal oxides protecting 23,52,53 or passivating layers. 54 A classical protection strategy is the deposition of a few nm of thin amorphous TiO 2 layer by atomic layer deposition (ALD), 23,26,49,55,56 allowing to control the thickness and improve the homogeneity of the surface layer. We therefore deposited an amorphous TiO 2 layer, with a 8.3 nm thickness measured by ellipsometry (Fig.…”

Enhanced Photoelectrochemical Water Splitting by Surface Modified Electrodeposited n‐Cu2O Thin Films

“…It owes intriguing optical [ 1 ] and electrical properties [ 2 ] which tends the investigators to draw their attention to develop its applications in photovoltaic [ 3,4 ] and photoelectrochemical (PEC) devices. [ 5,6 ] A low cost and efficient solar energy to chemical energy conversion possibility via hydrogen generation is one of the most important and prominent research areas today. [ 6–8 ] This will definitely provide an opportunity to store intermittent solar energy as hydrogen in large quantities and later use as an energy source when and where energy is required.…”

“…[ 5,6 ] A low cost and efficient solar energy to chemical energy conversion possibility via hydrogen generation is one of the most important and prominent research areas today. [ 6–8 ] This will definitely provide an opportunity to store intermittent solar energy as hydrogen in large quantities and later use as an energy source when and where energy is required. This is one of the most promising approaches for eliminating the use of environmentally harmful fossil fuel.…”