Decoupled Water Electrolysis Driven by 1 cm² Single Perovskite Solar Cell Yielding a Solar‐to‐Hydrogen Efficiency of 14.4 %

Abstract

Solar water splitting by photovoltaic (PV) electrolysis is a promising route for sustainable hydrogen production. However, multiple PV cells connected in series are generally required to fulfil the practical electrolytic voltages, which inevitably increases the system complexity and resistance. Decoupled water electrolysis for separate hydrogen and oxygen evolution needs smaller voltage to drive each half-reaction, which provides a feasibility to achieve the single PV cell driven water electrolysis. Herein, by introducing sodium nickelhexacyanoferrate (Na-NiHCF) as the redox mediator, decoupled acid water electrolyzer and amphoteric water electrolyzer were respectively constructed. The required voltages for the hydrogen or oxygen evolution steps matched with the output voltages of the perovskite solar cell (PSC). Impressively, by combining one 1 cm 2 FAPbI 3 -based PSC (efficiency: 18.77 %) with the decoupled amphoteric water electrolyzer, a solar-to-hydrogen (STH) efficiency of 14.4 % was achieved, which outperformed previously reported PSC-driven water electrolysis cells.

Decoupled electrolysis for hydrogen production and hydrazine oxidation via high-capacity and stable pre-protonated vanadium hexacyanoferrate

“…As displayed in Fig. 3e , the p-VHCF mediator electrode depicts better cycling stability in terms of capacity retention and cycle number than most previously reported redox mediator electrodes for acid water electrolysis (Supplementary Table S1 ) 16 , 17 , 37 – 41 .…”

“…For instance, our previous work presented a sodium nickelhexacyanoferrate mediator to decouple acid water electrolysis and amphoteric water electrolysis. The decoupled device was driven by one single perovskite solar cell with a solar-to-hydrogen efficiency of 14.4% 16 . Ma et al introduced a Prussian blue analogs of Cu[Fe(CN) 6 ] 2/3 ·3.4H 2 O (CuFe TBA) as a solid-state redox mediator to decouple the HER and OER in acid water electrolysis.…”

Photovoltaic-driven Ni(ii)/Ni(iii) redox mediator for the valorization of PET plastic waste with hydrogen production

“…Moreover, the integration of photovoltaics (PV) and electrolysis represents a promising approach for harnessing intermittent solar energy sources. 40,41 In our previous study, our solar-powered PV-electrochemical system exhibited an impressive solar-to-chemical (STC) efficiency when upcycling PET plastic waste. 42 Building upon these investigations, we now illustrate the construction of a solar-powered PET upcycling system by implementing a decoupling strategy, as depicted in Fig.…”

Breaking boundaries: advancements in solid-state redox mediators for decoupled water electrolysis

“…Finally, the authors constructed a photovoltaic water electrolysis device to achieve direct solar-to-hydrogen energy conversion, but the efficiency of solar energy conversion to hydrogen energy was not reported. A similar concept using sodium nickelhexacyanoferrate (NaNiHCF) as an RM in the decoupling strategy was proposed by Zhao et al 72 Unusually, a self-developed perovskite solar cell was employed as an energy input in a photovoltaic decoupled water electrolysis system, with a solar hydrogen production efficiency of 14.4%, which is superior to that of previously reported perovskite solar cell driven water electrolysis cells.…”