One-step pyrolysis construction of CoP/P-doped biomass-derived carbon composite catalysts for efficient oxygen evolution reaction

Abstract

Constructing an intimate active component-support interface to enhance the electronic interaction is an effective strategy for designing efficient oxygen evolution reaction (OER) electrocatalysts. In this work, Chinese fir sawdust was used as the carbon precursor and phytic acid was employed as both the phosphorus source and coordinating agent to in situ construct CoP/P-doped biomass-derived carbon composite catalysts (CoP -x @PBC) via a one-step pyrolysis strategy. This strategy not only enables the stable formation of the CoP phase and P doping in the carbon matrix, but also endows the catalysts ith abundant pores and structural defects, thereby creating an intimate CoP and PBC interface. The intimate interface significantly enhances the interfacial electronic interaction and charge-transfer capability between CoP and PBC, effectively promotes surface reconstruction, and consequently enables CoP -x @PBC to exhibit high OER catalytic performance. Among the prepared catalysts, CoP -1.5 @PBC shows the most favorable OER activity, requiring 273 mV to reach 10 mA cm −2 , with a Tafel slope of 59.8 mV dec −1 and stable operation for 100 h. After long-term OER testing, CoOOH-dominated active species are formed on the surface of CoP -1.5 @PBC, while the CoP crystalline phase and biomass-derived carbon framework remain well preserved, demonstrating both high catalytic activity and structural stability. This work realizes the one-step in situ construction of CoP -x @PBC catalysts and provides a new insight into the design of biomass-carbon-supported metal phosphide electrocatalysts with strong interfacial electronic interactions.