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

The Bi 2 MoO 6 (BMO) nanosheet array on nickel foam was synthesized via hydrothermal method. Subsequently, the NH 3 plasma modification was utilized to enable synchronous N doping and O vacancies on the surface of BMO (N-BMO). The nanosheet structure and numerous O defects could provide sufficient active sites for adsorbed ions (especially in alkaline electrolyte). Used for supercapacitors, such N-BMO electrode achieved more than twice capacitance than pristine BMO. Compared with BMO, the N-BMO further revealed enhanced catalytic activity during oxygen evolution reaction process. • Bi 2 MoO 6 nanosheet array was synthesized through one-step hydrothermal method. • O defects and N doping (N-BMO) were achieved through NH 3 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 Bi 2 MoO 6 nanosheets with adequate oxygen vacancies and heteroatom nitrogen injection were synthesized via hydrothermal reaction and subsequent NH 3 /Ar plasma modification. Controllable generation of O vacancies and injection of N atoms in Bi 2 MoO 6 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 Bi 2 MoO 6 , the plasma engraved Bi 2 MoO 6 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. [ABSTRACT FROM AUTHOR]