In situ Ni-doped CoMoO4 nanomaterials on acid-pretreated nickel foam with high capacitive properties

Different from conventional methods that synthesize Ni-doped nanomaterials by introducing external Ni sources, this study developed an in-situ doping strategy using Hydrochloric acid , nitric acid , sulfuric acid, and oxalic acid treatments generated corresponding nickel salts (NiCl 2 , Ni(NO 3 ) 2 , NiSO 4 , and NiC 2 O 4 ) on nickel foams as Ni sources, enabling one-step hydrothermal synthesis of Ni-doped CoMoO 4 nanoelectrodes . The in situ Ni-doped CoMoO 4 nanomaterials synthesized on the four acidified pretreated nickel foams exhibited specific capacitances of 4680, 4500, 2700, and 2250 mF cm −2 at 5 mA cm −2 , respectively, significantly exceeding the 1690 mF cm −2 achieved by undoped CoMoO 4 on conventional clean foams. An asymmetric supercapacitor (ASC) assembled with activated carbon and Ni-doped CoMoO 4 electrode material synthesized on hydrochloric acid pretreated nickel foam demonstrated a specific capacitance of 690 mF cm −2 at 5 mA cm −2 , along with a high energy density of 160.4 Wh·kg −1 at 2600 W kg −1 power density. Remarkably, the ASC retained 95 % capacitance after 10,000 cycles. These results highlight the potential of in-situ Ni-doped CoMoO 4 as a high-performance electrode material for advanced supercapacitors . • In situ Ni doped CoMoO 4 was synthesized on four acidified pretreated nickel foams. • Acid pretreatment of nickel foam alters the morphology of CoMoO 4 . • Pretreatment of nickel foam improves the capacity and cycling stability of CoMoO 4 .