Solvent-exchange-assisted activation of Cu-1,4-benzene dicarboxylate metal-organic framework for use as a bifunctional water splitting electrocatalyst

•Cu-1,4-benzene dicarboxylate was successfully synthesized via facile cathodic electrodeposition method.•The strongly coordinating DMF molecules were properly removed through solvent-exchange-assisted activation technique.•HER and OER performances of the activated Cu(BDC) in alkaline media demonstrated efficiency of the proposed activation method.•The mesoporous architecture with plentiful active sites was responsible for the best electrocatalytic properties. The activation of metal-organic frameworks (MOFs) to eliminate extra-coordinating and pore-filling solvent molecules is essential before using MOFs in catalysis applications. Herein, we developed a solvent-exchange-assisted technique to activate cathodically electrodeposited MOF containing Cu nodes and 1,4-benzene dicarboxylate (BDC) linkers, known as Cu(BDC). This method was initially executed by washing electrodeposited MOF film in ethanol and acetone, followed by soaking in dichloromethane and applying heat treatment at a low temperature to remove strongly coordinating N,N-dimethylformamide (DMF) molecules, thereby properly accessing a well-arranged mesoporous architecture with abundant active sites toward electrocatalysis. The emergence of open-state Cu centers through this safe activation method offers a catalyst with enhanced electrocatalytic performance that displays low overpotentials of only 212 mV and 341 mV at a current density of 10 mA.cm−2 toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Importantly, this study paves a way for developing low-cost methods for production and activation of MOFs for high efficient and stable alkaline water splitting. [Display omitted]