Yang Zhang,Ning Cao,Caihao Wang,Chaocheng Zhao,Yongqiang Wang,Shiyong Zhao,Jinqiang Zhang
Photocatalytic oxygen evolution reaction (OER) is pivotal for sustainable energy systems yet lacks high-performance catalysts capable of strong visible light absorption, robust charge dynamics, fast reaction kinetics, and high oxidation capability. Herein, we report the multiscale optimization of carbon nitride through the construction of porous curled carbon nitride nanosheets (CNA-B30) incorporating boron center/cyano group Lewis acid-base pairs (LABPs). The unique chemical and structural features of CNA-B30 extended the photoabsorption edges of π → π* and n → π* electronic transitions to 470 nm and 715 nm, respectively. Planar distortion and LABPs induced charge redistribution, enhancing the built-in electric field to promote efficient charge dissociation and transport. Moreover, boron atoms elevated the valence band of carbon nitride and served as active oxidation sites, effectively lowering the thermodynamic barrier for water oxidation. As a result, CNA-B30 demonstrated outstanding OER activity, achieving 586.5μmol g −1 h −1 (λ > 420 nm) without co-catalysts. With the addition of a Co co-catalyst, the oxygen evolution rate increased to 2085.5 μmol g −1 h −1 (λ > 420 nm), and an apparent quantum efficiency of 5.8 % at 420 nm, surpassing most state-of-the-art OER photocatalysts. This work offers valuable insights into designing advanced OER photocatalysts for efficient solar fuel production.
Xingfa Zeng,Linna Dong,Jifang Fu,Liya Chen,Jia Zhou,Peisong Zong,Guozhen Liu,Liyi Shi
Low coulombic efficiency and serious safety issues due to uncontrollable lithium dendrite growth has severely impeded the practical application of lithium-ion batteries (LIBs) with lithium metal as the anode. In this work, we design and fabricate a novel single ion conducting crosslinked polymer gel electrolytes containing negatively charged delocalized state borate structures and rich EO units via one-step photoinitiated in-situ radical polymerization in presence of PVDF-HFP as reinforcing materials. Herein, we synthesize a novel lithium bis(macid acid) borate to give anion covalently bonded to the polymer main chain and vinyl monomers containing rich EO units are chosen to build polymer framework to ensure fast ion transport. As expected, the tailored boron-centered single-ion-conducting polymer gel electrolytes exhibit high ionic conductivity up to 1.03×10 −3 S cm −1 at 32 °C, excellent oxidation potential up to 5.05 V vs Li + /Li at 1 mV/s, and a near-single ion conducting behavior (lithium ion transference number of 0.65). The Lithium (Li) metal symmetric cells assembled with the novel boron-centered single-ion-conducting polymer gel electrolytes show long-term stable cycling over >700 h at room temperature without short circuit, which implies the excellent stability of blend membranes during lithium metal deposition and stripping processes. Moreover, the Li/LiFePO 4 cells assembled with the boron-centered single-ion-conducting polymer gel electrolytes exhibit excellent rate performance and cycling performance. The initial discharge capacity is 161.3 mAh g −1 at 0.1 C and a capacity of 127.7 mAh g −1 maintains with nearly 100% coulombic efficiency after 100 cycles. Moreover, the Li/LiFePO 4 cells deliver stable coulombic efficiency close to 100% at 0.5 C after 300 cycles.
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