CuO-Functionalized Silicon Photoanodes for Photoelectrochemical Water Splitting Devices

Abstract

One of the main difficulties for the technological development of photoelectrochemical (PEC) water splitting (WS) devices is the synthesis of active, stable and cost-effective photoelectrodes that ensure high performance. Here we report the development of a CuO-based photoanode, which shows an onset potential for the water oxidation of 0.53 V vs. SCE at pH 9, which implies an overpotential of only 75 mV, and high stability above 10 hours. The photoanodes have been fabricated by sputtering a thin film of Cu 0 on commercially available n-type Si wafers, followed by a photoelectrochemical treatment in basic pH conditions. The resulting CuO/Cu layer acts as: (i) protective layer to avoid the corrosion of nSi, (ii) p-type hole conducting layer for efficient charge separation and transportation, and (iii) electrocatalyst to reduce the overpotential of the water oxidation reaction. The low cost, low toxicity and good performance of CuO-based coatings can be an attractive solution to functionalize unstable materials for solar energy conversion

Remarkable Improvement in Water Oxidation Catalysis by Moderate Heat Treatment of a Crystalline Silver‐Based Thin Film Developed In‐Situ From Silver‐ions in Acetate Solution

“…[9][10][11][12][13][14][15][16][18][19][20][21][22][23][25][26][27][28][29][30][31][32][33][34][35][36] For example by the use of electrodeposition method, several efficient catalysts for OER were obtained from Co, Cu and Ni with catalytic water oxidation showing overpotential (h) in the range of 320-470 mV and encouraging performances were observed when this metal oxides were integrated with silicon photoanode. [49][50][51][52] Despite of these achievements, to date, complexes and materials based on Ru and Ir are the most efficient catalysts [40][41][42][43][44][45][46][47] known for OER among reported ones though their low abundance and high costs impede their broad applications. As a consequence, it is highly desirable to develop new catalysts for OER based on abundant materials with low overpotentials, efficient activity and high durability.Silver is a second row transition metal and has been valued throughout history for many of its properties that are useful to humans.…”

In Situ Fabrication of Nanoepitaxial TiO2 Protection Layer on Si Substrate: Hole Chemical Conduction Instead of Tunneling Effect

“…When it is used as a photoanode, crystalline silicon must be stabilized against corrosion or passivation in alkaline solution . For these purposes, introducing a heterogeneous coating, such as Ni, MnO x , NiO x , TiO 2 , Co/Co‐Pi, ITO, CuO, Cu, and Ti, on the Si surface is an efficient approach. In comparison with other materials, TiO 2 shows several advantages, including good light transmission property, efficient carrier transfer, low cost, and non‐toxicity.…”

Activation pathways taking place at molecular copper precatalysts for the oxygen evolution reaction

“…It appears that the bdmpza ligand has clear effect on the stability of the copper particles that are formed, and seems to prevent solvation of Cu 2+ upon reoxidation of copper to the +II oxidation state. In line with such a hypothesis the presence of concentrated solutions of carbonate [54] and especially borate [34,55] have a dramatic influence on the stability and therefore activity of copper deposits under oxidative conditions. It seems that similar to coordinating anions, the bdmpza ligand has a stabilizing effect on copper oxide versus solvation, thereby posing an interesting application of the use of organic ligands and/or additives in heterogeneous water oxidation chemistry.…”