Capturing Visible Light in Low‐Band‐Gap C4N‐Derived Responsive Bifunctional Air Electrodes for Solar Energy Conversion and Storage. (30th June 2021)

• Record Type: Journal Article
• Authors: Fang, Zhengsong; Li, Yuan; Li, Jing; Shu, Chenhao; Zhong, Linfeng; Lu, Shaolin; Mo, Chunshao; Yang, Meijia; Yu, Dingshan
• Is Part Of: Angewandte Chemie. Volume 133:Number 32(2021)
• Page Start: 17756
• Page End: 17762
• Publication Date: 2021-06-30
• Subjects: oxygen evolution reaction -- oxygen reduction reaction -- photocoupled batteries -- rechargeable air batteries -- solar energy conversion and storage; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202104790
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We report facile synthesis of low‐band‐gap mesoporous C4 N particles and their use as responsive bifunctional oxygen catalysts for visible‐light‐sensitive (VLS) rechargeable Zn‐air battery (RZAB) and polymer‐air battery (RPAB). Compared to widely studied g‐C3 N4, C4 N shows a smaller band gap of 1.99 eV, with a larger photocurrent response, and it can function as visible‐light‐harvesting antenna and bifunctional oxygen reduction/evolution (ORR/OER) catalysts, enabling effective photocoupling to tune oxygen catalysis. The C4 N‐enabled VLS‐RZAB displays a low charge voltage of 1.35 V under visible light, which is below the theoretical RZAB voltage of 1.65 V, corresponding to a high energy efficiency of 97.78 %. Pairing a C4 N cathode with a polymer anode also endows an VLS‐RPAB with light‐boosted charge performance. It is revealed that the ORR and OER active sites in C4 N are separate carbon sites near pyrazine‐nitrogen atoms and photogenerated energetic holes can activate OER for improved reaction kinetics. Abstract : A narrow‐band‐gap C4 N material was explored as a visible‐light‐sensitive (VLS) organic bifunctional oxygen catalyst for application in photocoupled secondary batteries. The C4 N‐enabled VLS rechargeable zinc‐air batteries (RZAB) and all‐polymer polymer‐air batteries (RPAB) exhibited markedly reduced charge voltage together with an increased energy efficiency under visible light.