Plasma engraved Bi2MoO6 nanosheet arrays towards high performance supercapacitor and oxygen evolution reaction

Highlights: • Bi₂MoO₆ nanosheet array was synthesized through one-step hydrothermal method. • O defects and N doping (N-BMO) were achieved through NH₃ plasma modification. • The N-BMO electrode delivered high capacitance retention (79.0% of capacitance retention after 10,000 cycles at 20 Ag⁻¹). • The N-BMO exhibited good catalytic activity with small Tafel slope of 42 mV dec^–1. Benefiting from tailorable component and structure, metal oxides exhibit great impetus towards high performance supercapacitors and oxygen evolution reaction catalyst. However, rational structural regulation of metal oxides-based electrode under mild conditions to simultaneously achieve abundant active sites and synergistic effects of multiple active centers is still very challenging. In this study, the Bi₂MoO₆ nanosheets with adequate oxygen vacancies and heteroatom nitrogen injection were synthesized via hydrothermal reaction and subsequent NH₃/Ar plasma modification. Controllable generation of O vacancies and injection of N atoms in Bi₂MoO₆ was conducive to regulating the band structure of electrode material, achieving greatly enhanced conductivity, wettability, ionic infiltration capacity and significantly reduced dissociation barrier of surface adsorbates. Compared with pristine Bi₂MoO₆, the plasma engraved Bi₂MoO₆ electrode delivered superior charge storage performance for supercapacitor (79.0% of capacitance retention after 10,000 cycles at 20 Ag⁻¹) and good electrochemical catalytic efficiency for oxygen evolution reaction (349 mV at 10 mA cm⁻² with a Tafel slope of 42 mV dec^–1). It is demonstrated that the plasma modification for metal oxides is a promising application in supercapacitors and electrochemical water splitting.