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Conformally Coated Nickel Phosphide on 3D, Ordered Nanoporous Nickel for Highly Active and Durable Hydrogen Evolution
ACS Sustainable Chemistry & Engineering ( IF 7.1 ) Pub Date : 2020-11-10 , DOI: 10.1021/acssuschemeng.0c05192
Anand P. Tiwari 1 , Kisung Lee 1 , Kisun Kim 1 , Jin Kim 1 , Travis G. Novak 1 , Seokwoo Jeon 1
Affiliation  

Microstructuring is an effective strategy to manipulate the active sites of electrocatalysts to improve their performance, but there are few reports that focus on continuous three-dimensional (3D) nanopatterning. Herein, 3D continuous nanopatterns with a pore size of 100 nm of nickel phosphide are fabricated and evaluated for acidic electrocatalytic hydrogen evolution reaction (HER). The 3D continuous nanopatterned catalyst requires a minimum overpotential of 101 mV to achieve a current density of 10 mA·cm–2 and a Tafel slope of 60 mV·dec–1, which outperforms most electrocatalysts based on transition metal derivatives. The turnover frequency of nanopatterns is 0.87 s–1 at an overpotential of 100 mV, which is very close to benchmark electrocatalyst Pt/C (0.90 s–1). This nanopatterned catalyst also displays superior durability: up to 250 h of continuous operation without any decay. Experimental analysis suggests that nanopatterns of active materials expose more active sites, and high curvature (rc < 100 nm) of nanopores allows fast discharge of gas bubbles for fast and efficient production of H2 with high stability. Continuous, ordered nickel nanonetworks coated by the nickel phosphide also allow fast transportation of ions to facilitate the H* desorption process, contributing to improved kinetics for outstanding HER activity.

中文翻译:

在3D上共形涂覆的磷化镍,有序的纳米孔镍,可实现高活性和持久的氢气释放

微结构化是操纵电催化剂活性位点以提高其性能的有效策略,但是很少有报道关注连续的三维(3D)纳米图案。在此,制造了孔径为100 nm的磷化镍的3D连续纳米图案,并对其进行了酸性电催化氢释放反应(HER)的评估。3D连续纳米图案化催化剂要求最小过电势为101 mV,才能实现10 mA·cm –2的电流密度和60 mV·dec –1的Tafel斜率,这优于大多数基于过渡金属衍生物的电催化剂。纳米图案的转换频率为0.87 s –1在100 mV的超电势下,非常接近基准电催化剂Pt / C(0.90 s –1)。这种纳米图案催化剂还显示出卓越的耐久性:长达250小时的连续运行而无任何衰减。实验分析表明,活性材料的纳米图案暴露出更多的活性位点,并且纳米孔的高曲率(r c <100 nm)允许快速释放气泡,从而以高稳定性快速有效地生产H 2。连续的,有序的,被磷化镍覆盖的镍纳米网络还允许离子的快速传输,以促进H *的解吸过程,从而有助于改善动力学,从而实现出色的HER活性。
更新日期:2020-11-23
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