Abstract
Solvothermal synthesis of pristine and Zn-doped NiO nanocluster electrocatalysts have been synthesized for efficient electrochemical water splitting applications. Cubic structure with lattice constant of 4.16 A° was revealed through XRD analysis. Presence of oxygen vacancy was confirmed by employing PL study. Nanosheets combined feather like nanocluster morphology was obtained for optimized electrocatalysts. Variation in optical absorption and energy band gap was observed for undoped and Zn-doped NiO electrocatalysts. Highest specific capacitance of 455.74 F/g at 5 mV/s scan rate was obtained for 10% Zn-doped NiO nanoclusters. Improved oxygen evolution was achieved for the same electrocatalysts by addressing the current density of 0.77 mA/g at 10 mV/s with lowest Tafel slope of 75 mV/decade. Higher conductivity with lower internal resistance (
R
s
) of 10.36 Ω was obtained for the above optimized electrocatalyst. Practically applicable stability over 12 h of 10% Zn-doped NiO nanocluster electrocatalyst was proposed for efficient electrochemical water splitting applications.
Graphical abstract clearly revealed the water oxidation and electrochemical pseudo capacitive behavior of the best performed 10% Zn-doped NiO nanoclusters electrocatalysts.
Highlights
Highest specific capacitance of 455.74 F/g at 5 mV/s was obtained.
Improved oxygen evolution was achieved by 0.77 mA/g at 10 mV/s.
Obtained higher conductivity with lower internal resistance (
R
s
) of 10.36 Ω.