Science News: 2021 Nat. Commun., How O-BP electrocatalyst protect MAPbI3 perovskite and achieve high stability?
Nature Communications (IF 14.919) published the research results of Ji-Wook Jang, Dongrak Oh, etc. of the National Ulsan Institute of Science and Technology (UNIST) in South Korea in November 2021. The research team combined oxidised buckypaper and perovskite photocathode to create an unassisted solar device and produce hydrogen peroxide.
Hydrogen peroxide (H2O2) is a promising environmentally friendly oxidant with an energy density comparable to that of compressed H2. The current H2O2 production strategy is mainly the anthraquinone oxidation process, which requires a lot of energy and organic chemicals. Another simple and environmentally friendly method is to reduce O2 to H2O2 based on a photocatalyst. However, the conversion efficiency of solar energy to H2O2 is limited by two factors, including the low performance of the photoelectrode and the low selectivity and stability of the electrocatalyst. In this study, the research team selected oxidised buckypaper (O-BP) as the electrocatalyst, and successfully used Field’s metal (FM) to passivate the high-performance MAPbI3 perovskite (PSK) photocathode. The O-BP electrocatalyst connected via FM effectively protects the PSK and prevents water penetration.
The research team used a solar simulator to analyze the photovoltaic characteristics and used a quantum efficiency measurement system for spectral analysis. At the same time, the short-circuit current under the solar simulator was compared with the Jsc (short-circuit current density) of QE system to prove the authenticity of the experiment. The research results showed that under the condition of regular supply of fresh electrolyte, the H2O2 production selectivity of O-BP electrocatalyst was close to 100% and held good stability within 100 hours. In addition, the research team used a two-electrode system containing O-BP/FM/PSK photocathode and a-NiFeOx anode to demonstrate unassisted solar H2O2 production. Its solar-to-chemical (H2O2) conversion efficiency (SCC) was ~1.463%. The system was stable for 45 hours under 1-sun light and had 100% H2O2 production selectivity. The research team further explained that by optimizing PSK, ETL, HTL and electrocatalysts, the SCC(%) and stability of the entire system can be improved.
Carbon materials performance: characterisation and oxygen reduction.
O-BP-integrated PSK photocathode: characterisation and ORR activity.
