Surface Crystallization Enhancement and Defect Passivation for Efficiency and Stability Enhancement of Inverted Wide-Bandgap Perovskite Solar Cells.

Wide-bandgap (WBG) inverted perovskite solar cells (PSCs) are used as the top cell for tandem solar cells, which is an effective way to outperform the Shockley-Queisser limit. However, the low efficiency and poor phase stability still seriously restrict the application of WBG inverted PSCs. Here, the surface of the WBG perovskite film was passivated by the synthesized 1,2,4-tris(3-thienyl)benzene (THB). The THB size well matches with the halogen ion vacancy on the perovskite surface, and the S atom in THB can strongly interact with Pb2+ on the surface of the WBG perovskite film to the greatest extent, which effectively passivates surface defects and suppresses the recombination of carriers caused by these defects. At the same time, the S atom in THB occupied the migration site of the halogen ions, which inhibits the migration of halogen ions. Due to the strong conjugation effect and stability of THB, it can be locked on the surface of perovskite to increase the lattice strength and inhibit the segregation of photoinduced halide, thus improving the performance and operational stability of PSCs. The THB-modified WBG (Eg = 1.71 eV) PSC achieves a maximum power conversion efficiency of 20.75%, and its 99.0% is retained after 1512 h at a relative humidity of 10-25%. Under the irradiation of 1000 lx LED light, the indoor power conversion efficiency of the THB-modified WBG PSC reaches 34.15%.

Bifunctional ligand Co metal-organic framework derived heterostructured Co-based nanocomposites as oxygen electrocatalysts toward rechargeable zinc-air batteries.

Rational construction of efficient and robust bifunctional oxygen electrocatalysts is key but challenging for the widespread application of rechargeable zinc-air batteries (ZABs). Herein, bifunctional ligand Co metal-organic frameworks were first explored to fabricate a hybrid of heterostructured CoOx/Co nanoparticles anchored on a carbon substrate rich in CoNx sites (CoOx/Co@CoNC) via a one-step pyrolysis method. Such a unique heterostructure provides abundant CoNx and CoOx/Co active sites to drive oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), respectively. Besides, their positive synergies facilitate electron transfer and optimize charge/mass transportation. Consequently, the obtained CoOx/Co@CoNC exhibits a superior ORR activity with a higher half-wave potential of 0.88 V than Pt/C (0.83 V vs. RHE), and a comparable OER performance with an overpotential of 346 mV at 10 mA cm-2 to the commercial RuO2. The assembled ZAB using CoOx/Co@CoNC as a cathode catalyst displays a maximum power density of 168.4 mW cm-2, and excellent charge-discharge cyclability over 250 h at 5 mA cm-2. This work highlights the great potential of heterostructures in oxygen electrocatalysis and provides a new pathway for designing efficient bifunctional oxygen catalysts toward rechargeable ZABs.

Recent advances in bifunctional dual-sites single-atom catalysts for oxygen electrocatalysis toward rechargeable zinc-air batteries.

Rechargeable zinc-air batteries (ZABs) with high energy density and low pollutant emissions are regarded as the promising energy storage and conversion devices. However, the sluggish kinetics and complex four-electron processes of oxygen reduction reaction and oxygen evolution reaction occurring at air electrodes in rechargeable ZABs pose significant challenges for their large-scale application. Carbon-supported single-atom catalysts (SACs) exhibit great potential in oxygen electrocatalysis, but needs to further improve their bifunctional electrocatalytic performance, which is highly related to the coordination environment of the active sites. As an extension of SACs, dual-sites SACs with wide combination of two active sites provide limitless opportunities to tailor coordination environment at the atomic level and improve catalytic performance. The review systematically summarizes recent achievements in the fabrication of dual-site SACs as bifunctional oxygen electrocatalysts, starting by illustrating the design fundament of the electrocatalysts according to their catalytic mechanisms. Subsequently, metal-nonmetal-atom synergies and dual-metal-atom synergies to synthesize dual-sites SACs toward enhancing rechargeable ZABs performance are overviewed. Finally, the perspectives and challenges for the development of dual-sites SACs are proposed, shedding light on the rational design of efficient bifunctional oxygen electrocatalysts for practical rechargeable ZABs.