PW6Mo6/ZIF-67@NF composite with exposed Co nodes as efficient oxygen evolution reaction electrocatalyst.

The construction of efficient, sustainable, and low-cost nonprecious metal electrocatalysts for oxygen evolution reaction (OER) is necessary for the realization of electrocatalytic overall water splitting. Herein, the PW 6 Mo 6 /ZIF-67@NF is prepared using a simple coprecipitation method. Characterization results indicate that the PW 6 Mo 6 induces the exposure of Co nodes in ZIF-67, which can act as catalytic active sites for OER. Meanwhile, the introduction of PW 6 Mo 6 improves the conductivity and electrochemical active surface area of ZIF-67, which further enhances the OER performance. The electrochemical test results show that the PW 6 Mo 6 /ZIF-67@NF exhibit an ultralow overpotential of 201 mV at 10 mA cm−2 and a small Tafel slope of 55 mV dec−1 for OER, which is lower than that of ZIF-67@NF (329 mV, 286 mV dec−1). Our study demonstrates the potential of polyoxometalate and ZIF composites to decrease the barriers of OER and provides a feasible approach for exploring economical and practical electrocatalysts. The etching of PW 6 Mo 6 induces the exposure of Co active sites in ZIF-67, thereby PW 6 Mo 6 /ZIF-67@NF exhibit an ultralow overpotential of 201 mV at 10 mA cm−2 and a small Tafel slope of 55 mV dec−1 for OER. [Display omitted] • The PW 6 Mo 6 /ZIF-67@NF with exposed Co nodes was successfully prepared using a coprecipitation method. • The introduction of PW 6 Mo 6 improved the conductivity and electrochemical active surface area of ZIF-67. • The ZIF-67 framework prevents the dissolution of PW 6 Mo 6 in the electrolyte, thus increasing the stability. • The PW 6 Mo 6 /ZIF-67@NF exhibited an ultralow overpotential and a small Tafel slope for OER. [ABSTRACT FROM AUTHOR]