Successes and Opportunities for Discovery of Metal Oxide Photoanodes for Solar Fuels Generators

Abstract

The importance of metal oxide photoanodes in solar fuels technology has garnered concerted efforts in photoanode discovery in recent decades, which complement parallel efforts in development of analytical techniques and optimization strategies using standard photoanodes such as TiO2, Fe2O3 and BiVO4. Theoretical guidance of high-throughput experiments has been particularly effective in dramatically increasing the portfolio of metal oxide photoanodes, motivating a new era of photoanode development where the characterization and optimization techniques developed on traditional materials are applied to nascent photoanodes that exhibit visible light photoresponse. The compendium of metal oxide photoanodes presented in the present work can also serve as the basis for further technique development, with a primary goal to establish workflows for discovery of materials that perform better against the critical criteria of operational stability, visible light photoresponse, and photovoltage suitable for tandem absorber architectures.

Overcoming Phase‐Purity Challenges in Complex Metal Oxide Photoelectrodes: A Case Study of CuBi2O4

“…[17,18] This exciting prospect has generated extensive high-throughput and combinatorial efforts to accelerate the discovery and study of new complex metal oxides photo absorbers for solar water splitting. [19][20][21][22][23][24] However, with rapidly increasing efforts toward finding new ideal compositions of photoabsorbers with enhanced properties, the number of different cations is very probable to increase. The cations may vary widely in size, oxidation state, and vapor pressure under heating treatment conditions.…”

Enhanced Bulk Transport in Copper Vanadate Photoanodes Identified by Combinatorial Alloying

“…The need to discover operationally stable photoanodes for solar fuels generation has led to expansive investigations over the past 10 years, yielding identification of dozens of photoactive materials. [1][2][3] Metal oxides remain the most promising class of materials due to their stability in the highly oxidizing oxygen evolution reaction (OER) environment. A concerted community effort has been identification of photoanodes with lower band gaps to broaden the spectral response, as required for efficient utilization of the solar resource.…”

In situ characterizations of photoelectrochemical cells for solar fuels and chemicals

“…Combinatorial synthesis coupled with high throughput electrochemistry has resulted in the discovery of many potential new photoelectrode candidates in recent years. 46,47 Additional study and optimization of such materials is crucial to the development of efficient PEC cells.…”