Copper oxide doped composite nanospheres decorated graphite pencil toward efficient hydrogen evolution electrocatalysis

• Preparation of cost-effective and efficient nanocomposite based electrocatalysts. • Characterization of electrocatalysts via different spectroscopic analyses. • Application of nanocomposite based electrocatalysts for OER and HER. • CuO-NiO/CN@GP exhibited the higher electrocatalytic activity. Cost-effective and efficient electrocatalysts for hydrogen generation are appealing and highly required. Here, we present copper oxide-nickel oxide nanospheres (CuO-NiO@GP), copper oxide-cobalt oxide nanospheres (Cu 2 O-Co 3 O 4 @GP), CuO-NiO/carbon nitride nanocomposite (CuO-NiO/CN@GP) and Cu 2 O-Co 3 O 4 /carbon nitride nanocomposite (Cu 2 O-Co 3 O 4 /CN@GP) decorated graphite pencil as effective electrocatalysts for oxygen and hydrogen evolution reactions (OER, HER). CuO-NiO@GP, Cu 2 O-Co 3 O 4 @GP, CuO-NiO/CN@GP and Cu 2 O-Co 3 O 4 /CN@GP were used as working electrode and revealed tremendous OER and HER activity at low over-potentials in KOH and H 2 SO 4 solutions. Among, CuO-NiO@GP, CuO-NiO/CN@GP, Cu 2 O-Co 3 O 4 @GP and Cu 2 O-Co 3 O 4 /CN@GP, the superior catalytic activity is displayed by CuO-NiO/CN@GP which gave current density of 20 mAcm −2 at potential of 1.411 V (overpotential = 0.181 V) by using 1.0 M KOH concentration. CuO-NiO/CN@GP demonstrated higher catalytic performance toward OER as comparing to CuO-NiO@GP, Cu 2 O-Co 3 O 4 @GP and Cu 2 O-Co 3 O 4 /CN@GP. Similarly, CuO-NiO/CN@GP need the lowest potential of −0.762 and −0.858 V to obtain the current density of 10 mAcm −2 and 20 mAcm −2 in HER catalytic performance utilizing 0.5 M H 2 SO 4 solution. Thus, it was observed from the LSVs of CuO-NiO@GP, CuO-NiO/CN@GP, Cu 2 O-Co 3 O 4 @GP and Cu 2 O-Co 3 O 4 /CN@GP that CuO-NiO/CN@GP shows greater catalytic activity and found more efficient and active in both OER and HER because CuO-NiO/CN@GP requires a low over potential, which produced 10 mAcm −2 and 20 mAcm −2 in both OER and HER. CuO-NiO/CN@GP demonstrates lower Tafel slopes of 171 mV dec −1 and 129 mV dec −1 in HER and OER, respectively.