Synthesis and Testing of Adapted Copper Oxide as Water Splitting Electrocatalyst

Abstract

Ill. the era of renewable energy. the deve lopment of an efficient and cost-effective catalyst for the water splitting reactions namely. hydrogen evolution rea!.:lion (HER) and oxygen evolution reaction (OER) is highly important. Hydrogen gas (H2) is the most efficient fenc\\able ent:rgy fuel, and tht! cheapest and readily available SOllrc~ for HI is water, Therefore, the role of electrocatalysts becomes vital for the industrial water splitting process to produce ~h fueL In the present work mixed CUO/CU20. was synthesized through a simple chemical method followed by its modification with different compositions (0.1 to 1.5%) of silver n8noparticJes (AglCuO/CU20). The synthesized material was investigated for its structural and morphological patterns using XRD and FTIR analyses. Next the materials were converted into thick ink form by sonicating them with suitable solvents. The resultant ink (paste) was deposited on a glassy carbon electrode (Oe) substrate and subjected to its electrochemical and e lectrocatalytic analysis. The prepared electrodes exhibited composition-controlled electrocatalytic oxygen evolution reaction (OER) activity in an alkaline medium with good stability and reproducibility. The OER activity of synthesized electrocatalysts was systematically evaluated in a lkaline medium by employing linear scnn voltamll1etry (LSV). cyclic voltammetry (ey) and electrochemical impedance spectroscopy (EIS) techniques on the modified GC working electrode. The onset potential orthe CuO/Cu20 was found to be 1.38V which on adaptation with Ag NPs reduced up to 0.70 V vs. RHE for the optimized composition (1 %Ag adapted CUO/CU20). Similarly, the overpotentiaJ of the unmodified CUO/CU20 was 49 1 mV which reduced to 267 mV for lhe optimized sample. Among all the synthesized electrocatalysts. 1 % Ag/CuOlCU20 exhibited highest OER activity with lowest overpotentiai and Tafel slope value. The impedance results fairly complemented tile electrochemkal analysis showing fast charge transfer for the I %Ag adapted composition.