On the stability enhancement of cuprous oxide water splitting photocathodes by low temperature steam annealing

Abstract

Given the intermittent nature of solar radiation, the large-scale use of solar energy requires an efficient energy storage solution. So far, the only practical way to store such large amounts of energy is in the form of a chemical energy carrier, i.e., a fuel. Photoelectrochemical (PEC) cells offer the ability to convert solar energy directly into chemical energy in the form of hydrogen. Cuprous oxide (Cu2O) is being investigated for photoelectrochemical solar water splitting since it has a band gap of 2.0 eV with favorable energy band positions for water cleavage; it is abundant and environmentally friendly. A major challenge with Cu2O is its limited chemical stability in aqueous environments. We present a simple and low-cost treatment to create a highly stable photocathode configuration for H2 production, consisting of steam treatment of the multilayer structures. The role of this treatment was investigated and the optimized electrodes have shown photocurrents over-5mA cm-2 with 90% stability over more than 50 h of light chopping (biased at 0 VRHE in pH 5 electrolyte). 2

Electrolyte-less design of PEC cells for solar fuels: Prospects and open issues in the development of cells and related catalytic electrodes

“…To note that a passivation layer can improve the charge-separation and transfer processes across semiconductor-liquid interfaces [139]. Specific annealing treatments may also improve stability, for example in cuprous oxide water photocathodes by low temperature steam annealing [140], but still long-term stability is an issue.…”

Atomic Layer Deposition of Bismuth Vanadates for Solar Energy Materials

“…Typically, two reactants are used to deposit binary compounds such as M x O y where, for example, [M-O] cycles of metal and oxidant pulses are repeated to deposit conformal nanoscale layers. These capabilities have enabled significant progress for Fe 2 O 3 , [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Cu 2 O, [27][28][29][30] and other photoelectrodes. [6,31,32] There is a significant design advantage to using composite host-guest nanostructures for light-harvesting materials with low carrier mobilities.…”

Electrocatalytic oxidation of cyanide on copper-doped cobalt oxide electrodes

“…In addition, they are very attractive for multiple electrochemical processes and devices [6][7][8][9][10][11]. Despite such relevance, however, their utilization as electrodes and/or electrocatalysts in electrolytic treatments is greatly restricted by their low mechanical and electrochemical stability [6,[11][12][13]. Hence, the design and development of robust and stable Cubased electrocatalysts may bring a new generation of active components for multiple electrochemical devices and applications.…”