Transition-metal hydroxide nanosheets with peculiar double-layer structures as efficient electrocatalysts
Transition-metal hydroxide nanosheets with peculiar double-layer structures as efficient electrocatalysts
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DOI：
10.1016/j.checat.2022.02.015
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发表时间：
2022-04-21
期刊：
影响因子：
--
通讯作者：
Ma, Renzhi
中科院分区：
文献类型：
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作者：
Chen, Fashen;Zhou, Wei;Ma, Renzhi
具有分子级厚度的单层或多层纳米片可以为层数相关性质的基础研究提供理想的模型。本文报道了一种选择性合成具有特殊双层结构的含过渡金属Co-Fe和Co-Ni-Fe氢氧化铁纳米片的新策略。在铁的摩尔比固定为1/6的条件下，对水镁石型金属氢氧化物Co5/ 6Fe1/ 6(OH)(2)和Co2/3Ni1/6Fe1/ 6(OH)(2)进行拓扑化学氧化插层，得到了独特的第二阶段相。阴离子交换后，第二阶段的相被剥离成平均厚度约1.9 nm的双层氢氧化物纳米片，这大约是单层氢氧化物纳米片（约1.0 nm）的两倍。电催化实验和理论计算表明，双层氢氧化物纳米片具有优异的析氧反应（OER）催化活性和动力学，优于单层纳米片，这证实了具有可调成分和层数的过渡金属氢氧化物纳米片在高效电催化方面的巨大潜力。
Single- or few-layer nanosheets with amolecular- level thickness may provide an ideal model for the fundamental investigation of layernumber-dependent properties. Herein, we report a new strategy for a selective synthesis of transition-metal-containing Co-Fe and Co-Ni-Fe hydroxide nanosheets with peculiar double-layer structures. A unique second-stage phase was obtained from topochemical oxidative intercalation of brucite-type metal hydroxides, e.g., Co5/ 6Fe1/ 6(OH) (2) and Co2/3Ni1/6Fe1/ 6(OH)(2), with a molar ratio of Fe fixed at 1/6. After anion exchange, the second-stage phase was exfoliated into double-layer hydroxide nanosheets with an average thickness of similar to 1.9 nm, which was approximately twice that of their single-layer counterparts (similar to 1.0 nm). Electrocatalytic measurements combined with theoretic calculations revealed that the double-layer hydroxide nanosheets exhibited excellent oxygen evolution reaction ( OER) catalytic activity and kinetics, outperforming their single-layer counterparts, which validates the great potential of transition- metal hydroxide nanosheets with both tunable composition and layer numbers for efficient electrocatalysis.