Heterogeneous Bimetallic Phosphide Ni2P-Fe2P as an Efficient Bifunctional Catalyst for Water/Seawater Splitting
Heterogeneous Bimetallic Phosphide Ni2P-Fe2P as an Efficient Bifunctional Catalyst for Water/Seawater Splitting
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DOI：
10.1002/adfm.202006484
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发表时间：
2020-09-28
影响因子：
19
通讯作者：
Ren, Zhifeng
中科院分区：
文献类型：
--
作者：
Wu, Libo;Yu, Luo;Ren, Zhifeng
开发用于大规模水电解的高性能和具有成本效益的双功能电催化剂是期望的，但仍然是一个重大的挑战。大多数现有的纳米和微米结构的电催化剂需要复杂的合成程序，使得规模扩大极具挑战性。在此，通过将泡沫镍直接浸泡在盐酸和硝酸铁溶液中，然后进行磷化来合成非均相Ni 2 P-Fe 2 P微片。该催化剂具有高的本征活性、丰富的活性中心和上级的传递系数，在1 mKOH溶液中，电流密度分别为100和500 mA cm（-2），所需电压分别为1.682和1.865 V。这样的催化性能比基准IrO 2更上级||Pt/C对，并且也将该电催化剂置于迄今为止报道的最好的双功能催化剂之中。此外，其增强的耐腐蚀性和亲水表面使其适合海水裂解。它能够在1 mKOH海水中分别在1.811和2.004 V的电压下实现100和500 mA cm（-2）的电流密度，这与其坚固的耐用性一起，证明了其在现实海水电解中的巨大潜力。本工作提出了一个通用的和经济的方法对制造的非均相金属磷化物催化剂的水/海水电催化。
Developing high-performance and cost-effective bifunctional electrocatalysts for large-scale water electrolysis is desirable but remains a significant challenge. Most existing nano- and micro-structured electrocatalysts require complex synthetic procedures, making scale-up highly challenging. Here, a heterogeneous Ni2P-Fe2P microsheet is synthesized by directly soaking Ni foam in hydrochloric acid and an iron nitrate solution, followed by phosphidation. Benefiting from high intrinsic activity, abundant active sites, and a superior transfer coefficient, this self-supported Ni2P-Fe2P electrocatalyst shows superb catalytic activity toward overall water splitting, requiring low voltages of 1.682 and 1.865 V to attain current densities of 100 and 500 mA cm(-2)in 1mKOH, respectively. Such catalytic performance is superior to the benchmark IrO2 || Pt/C pair and also places this electrocatalyst among the best bifunctional catalysts reported thus far. Furthermore, its enhanced corrosion resistance and hydrophilic surface make it suitable for seawater splitting. It is able to achieve current densities of 100 and 500 mA cm(-2)in 1mKOH seawater at voltages of 1.811 and 2.004 V, respectively, which, together with its robust durability, demonstrates its great potential for realistic seawater electrolysis. This work presents a general and economic approach toward the fabrication of heterogeneous metallic phosphide catalysts for water/seawater electrocatalysis.