Highly Mesoporous Cobalt-Hybridized 2D Cu₃P Nanosheet Arrays as Boosting Janus Electrocatalysts for Water Splitting

Abstract

Recently, developing economical electrocatalysts with high performance in water decomposition has become a research hotspot. Herein, two kinds of cobalt-hybridized Cu 3 P nanostructure array electrocatalysts (including highly mesoporous 2D nanosheets and sugar gourd-like 1D nanowires) were controllably grown on a nickel foam substrate through a simple hydrothermal method combined with a subsequent phosphating treatment method. An electrocatalytic test indicated that the as-prepared 2D nanosheet array exhibited excellent activity and stability toward hydrogen evolution reaction under alkaline conditions, which offered a low overpotential of 99 mV at 10 mA/cm 2 and a small Tafel slope of 70.4 mV/dec, whereas a competitive overpotential of 272 mV was required for oxygen evolution reaction. In addition, the 2D nanosheet array delivered a low cell voltage of 1.66 V at 10 mA/cm 2 in a symmetric two-electrode system, implying its huge potential in overall water decomposition. The electrocatalytic performance is superior to the as-prepared 1D nanowire array and most of the Cu 3 P-related electrocatalysts previously reported. Experimental measurements and first-principles calculations show that the excellent performance of the 2D nanosheet array can be attributed to its unique 2D mesoporous structure and hybridization of cobalt, which not only provide a large electrochemically active surface and fast electrocatalytic reaction kinetics but also weaken the binding strength of electrocatalytic reaction intermediates. The present study provides a simple and controllable approach to synthesize Cu 3 P-based bimetallic phosphide nanostructures, which can be used as boosting Janus electrocatalysts for water decomposition.

A processable Prussian blue analogue-mediated route to promote alkaline electrocatalytic water splitting over bifunctional copper phosphide

“…As mentioned above, CH@PBA-P/CF exhibits the best catalytic performances toward the HER and OER among the as-prepared electrocatalysts, which are also comparable with those of copper-based electrocatalysts reported in the previous literature (Table S2†), such as CF supported Cu 3 P/Ni 2 P heterostructure, 42 porous Co–Cu–P on nickel foam, 45 and monolithic Mn/Ni-doped Cu 2 S. 46 Therefore, we achieved a two-electrode configuration using CH@PBA-P/CF as the both anode and cathode for overall water splitting. For comparison, the electrolytic cell using Pt/CF as the cathode and RuO 2 /CF as the anode was prepared as well.…”

Designing Janus catalysts for renewable energy-relevant bifunctional small molecule activation

“…58 Yuan and co-workers discovered Co-hybridized two-dimensional Cu 3 P nanosheets with an enhanced bifunctional HER/OER activity. 59 The electrochemical experiments with this material revealed that the presence of cobalt in the lattice improves the energy efficiency in either direction, as electrocatalytic HER and OER require 99 mV and 272 mV, respectively, to achieve 10 mA cm −2 current density. A low cell voltage of 1.66 V was recorded for the same two-dimensional nanosheet array for complete water-splitting at a constant current density of 10 mA cm −2 (Table 2).…”

Emerging 2D Copper‐Based Materials for Energy Storage and Conversion: A Review and Perspective

“…More recently, Liu et al prepared uniform cobalthybridized 2D Cu 3 P nanosheets (Co-Cu-P-NS) that were nearly vertically arranged on nickel foam. [439] As shown in Figure 25g, starting from a hydrothermally treated Co-Cu dihydroxide array, highly mesoporous 2D nanosheets and sugar gourd-like 1D nanowires were obtained by the phosphation process under the Ar plasma condition. The Co-Cu-P-NS exhibited an excellent electrocatalytic performance towards OER and HER, with an η OER,10 of 272 and η HER,10 of 72 mV in 1.0 m KOH, and a small Tafel slope of 83.2 and 70.4 mV dec −1 , respectively.…”

“…Copyright 2019, Elsevier. g-i) Reproduced with permission [439]. Copyright 2021, American Chemical Society.…”