Engineering surface states of hematite based photoanodes for boosting photoelectrochemical water splitting

Abstract

A critical review on how engineering surface states of hematite-based photoanodes can enhance the photoelectrochemical water splitting performance.

The role of carbon dots – derived underlayer in hematite photoanodes

“…Detailed calculation steps can be found elsewhere. 68,75 The k ct values for all samples (Fig. 7a) increase with increasing potentials.…”

“…IMPS is a useful tool for an in-depth exploration of the surface kinetics of charge transfer and recombination. 65,[75][76][77] The theory for the IMPS has been thoroughly discussed and demonstrated to be suitable for hematite photoanodes. 68,75 Fig.…”

“…65,[75][76][77] The theory for the IMPS has been thoroughly discussed and demonstrated to be suitable for hematite photoanodes. 68,75 Fig. 6a compares the IMPS spectra at 1.25 V vs. RHE for all samples, and the full IMPS dataset for hematite and H/UCDs (15) from 0.95 to 1.35 V vs. RHE are displayed in Fig.…”

Synergies of co-doping in ultra-thin hematite photoanodes for solar water oxidation: In and Ti as representative case

“…4,[11][12][13] However, pristine a-Fe 2 O 3 exhibits poor water splitting efficiency, far below the maximum theoretical efficiency of 12.9%, because of the mismatch between the valence band energy level and the water reduction potential, the short hole diffusion length of 2-4 nm and the low electron mobility. 8 Several strategies have been adopted to overcome the intrinsic limitations of hematite: 14 for instance, tuning the electrode morphology, 15 introduce synergistic interfaces in two-dimensional stacks of semiconductors, 16,17 surface activation with co-catalysts, 18 and doping with various metal cations to change the electronic structure. 19,20 Both nanostructuring and doping in a-Fe 2 O 3 photoanodes have been extensively investigated to improve its PEC properties.…”

In situ characterizations of photoelectrochemical cells for solar fuels and chemicals

“…59,[61][62][63][64][65][66] Such in situ PEC techniques help to unveil the underlying elementary charge transfer/recombination processes and reaction kinetics of the photoelectrodes. 63,67,68 Moreover, they also provide better insights into different losses associated with the photoelectrode as well as across the semiconductor/electrolyte interface (SEI) during the practical operation. Eventually, they provide a basis and fundamental understanding for the identification of benchmark photoelectrodes to further develop efficient PEC cells.…”