A Sandwich‐Like Organolead Halide Perovskite Photocathode for Efficient and Durable Photoelectrochemical Hydrogen Evolution in Water

Abstract

Organolead halide perovskite materials have demonstrated great potential in the solar cells field owing to their excellent optoelectronic properties. However, the instability issue of the perovskites impedes the translation of their attractive features for the solar fuel production such as photoelectrochemical H2 production from water splitting. Herein, CH3NH3PbI3 a photocathode with a sandwich‐like structure is fabricated with a general and scalable approach toward addressing this issue. The photocathode exhibits an onset potential at 0.95 V versus reversible hydrogen electrode (RHE) and a photocurrent density of −18 mA cm−2 at 0 V versus RHE with an impressive ideal ratiometric power‐saved efficiency of 7.63%. More impressively, the photocathode retains good stability under 12 h continuous illumination in water at wide pH range. This performance is much superior to that of the best perovskite‐based photoelectrode ever reported.

Graphite-protected CsPbBr3 perovskite photoanodes functionalised with water oxidation catalyst for oxygen evolution in water

“…14). In contrast to previous reports in the literature, which all reported constant decreasing photocurrent under continuous illumination 29,31 , we observed an increasing photocurrent during the measurement, especially in near-neutral pH, where the photoanode's current density gradually increased under illumination reaching a peak of 2.5 mA cm −2 after 16.7 h ( Supplementary Fig. 13).…”

“…FM was also used to protect a cesium formamidinium methylammonium (CsFAMA) halide perovskite-based photocathode in tandem with a BiVO 4 photoanode that showed stabilities of up to 20 h 30 . Finally, Zhang et al reported a CH 3 NH 3 PbI 3 -based photocathode encapsulated with Ti foil sputtered with Pt, which operated for 12 h under continuous illumination in water 31 . While some of these results appear promising, all of the approaches reported so far rely on expensive materials or sophisticated fabrication techniques.…”

Metal Halide Perovskites for Solar‐to‐Chemical Fuel Conversion

“…Titanium foil is another good choice for protecting halide perovskite photoelectrodes. Zhang et al fabricated a sandwich‐like structure by pasting Ti foil onto a MAPbI 3 ‐based photocathode (Figure c) . With Pt loaded as the catalyst, this photocathode exhibited an onset potential at 0.95 V versus RHE and a photocurrent density of 18 mA cm −2 at 0 V versus RHE, with an ideal ratiometric power‐saved efficiency of 7.63%.…”

Photoelectrochemical Water Splitting Reaction System Based on Metal-Organic Halide Perovskites

“…Nam et al [80] devised a perovskite-based photoanode for oxygen production with the Field's metal passivation; the device showed superior stability while maintaining an initial photocurrent of 93% after 5 h under AM 0.7 G sun and KOH solution (see Figure 10c). Zhang et al [84] designed a photocathode device with titanium foil passivation, which showed stable characteristics for 12 h, and notably, exhibited the same hydrogen evolution Faradaic efficiency for 2 h in a 0.5 M H 2 SO 4 solution (see Figure 10d). The second method, i.e., the passivation method using compact materials, prevents water from entering the perovskite layer by means of thin surface treatment.…”

“…Finally, the faradaic efficiency for the hydrogen evolution of the photocathode was calculated to be 95.1 ± 2.2%. Zhang et al [84] proposed a perovskite-based photocathode using titanium foil for the p-i-n type structure. The device used NiO as a hole transporting material, PCBM as an electron transporting material, and Ti foil as a passivation layer (see Figure 6c).…”