To improve overall electrochemical performance, we report and propose zinc cobaltite (ZnCo 2 O 4 ) nanowire arrays with a simple and precisely controllable NH 3 plasma treatment. The NH 3 plasma treatment effectively changes the electronic and chemical properties of the pristine ZnCo 2 O 4 by the nitrogen doping and surface functionalization simultaneously. By way of the nanoscale surface/electrical modification of ZnCo 2 O 4 , the nitrogen (N)-doped ZnCo 2 O 4 electrodes not only significantly enhanced the electrical conductivity but also increased the density of the hydroxyl group by appropriately controlling the Co 2+ /Co 3+ ratio (oxygen vacancies). Compared to pristine ZnCo 2 O 4 (1682.2 F g -1 at 5 A g -1 ), the N-doped ZnCo 2 O 4 electrode without conductive additives possessed high specific capacitance (3804.6 F g -1 at 5 A g -1 ), excellent rate capability (95.45% capacity retention at 40 A g -1 ), and good cycling stability (only 3.3% loss after 3000 cycles at 30 A g -1 ). These nanoscale surface state engineering methods may open a new avenue to optimize electrochemical performance for energy storage and conversion.
All Science Journal Classification (ASJC) codes
- Energy Engineering and Power Technology
- Chemical Engineering (miscellaneous)
- Materials Chemistry
- Electrical and Electronic Engineering