Phosphorus Incorporation into Co9S8 Nanocages for Highly Efficient Oxygen Evolution Catalysis

A highly active and stable oxygen evolution reaction (OER) catalyst with tunable charge density from Co2+ tetrahedral and Co3+ octahedral sites based on phosphorus doped Co9S8 nanocages is prepared by a sacrificial template method. P doping endows Co9S8 with increased electron density at the Fermi level, which improves electrical conductivity of Co9S8, thus improving the OER performance. AbstractThe improvement of activity of electrocatalysts lies in the increment of the density of active sites or the enhancement of intrinsic activity of each active site. A common strategy to realize dual active sites is the use of bimetal compound catalysts, where each metal atom contributes one active site. In this work, a new concept is presented to realize dual active sites with tunable electron densities in monometal compound catalysts. Dual Co2+ tetrahedral (Co2+(Td)) and Co3+ octahedral (Co3+(Oh)) coordination active sites are developed and adjustable electron densities on the Co2+(Td) and Co3+(Oh) are further achieved by phosphorus incorporation (P ‐Co9S8). The experimental results and density functional theory calculations show that the nonmetal P doping can systematically modulate charge density of Co2+(Td) and Co3+(Oh) in P ‐Co9S8 and simultaneously improve the electrical conductivity of Co9S8, which substantially enhances oxygen evolution reaction performance of P ‐Co9S8.

Source: Small - September 17, 2019 Category: Nanotechnology Authors: Bocheng Qiu, Lejuan Cai, Yang Wang, Xuyun Guo, Sainan Ma, Ye Zhu, Yuen Hong Tsang, Zijian Zheng, Renkui Zheng, Yang Chai Tags: Full Paper Source Type: research