Molybdenum and phosphorus Co-doped nanoarchitectonics on high-capacitance and durable activated carbon electrodes for advanced supercapacitor devices

Abstract

This study investigates the development of advanced carbon-based electrode materials for high-performance supercapacitors via phosphorus doping and molybdenum incorporation (Mo/P-TAC). Activated carbon-derived structures were modified to improve surface chemistry, porosity, and electrochemical behavior through heteroatom and metal doping. Benefiting from synergistic Mo and P effects, Mo/P-TAC delivered 268 F g- 1 at 0.8 A g- 1, about twice that of pristine carbon (116 F g- 1), and maintained good rate capability up to 4.0 A g- 1. P doping enhances surface wettability and introduces electroactive sites, while Mo incorporation promotes charge transfer and pseudocapacitive behavior. The synergistic interaction improves ion accessibility, conductivity, and electrochemical kinetics compared with single-doped or undoped carbon. The electrode retained 91.9% capacitance after 10,000 cycles at 4.0 A g- 1 and exhibited low charge-transfer resistance (1.29 k Omega versus 2.39 k Omega for carbon). The symmetric supercapacitor operated between -0.1 and + 0.9 V, delivering 69 F g- 1 at 0.8 A g- 1, 9.6 Wh kg- 1 energy density, and 2240 W kg- 1 power density, with 87.3% retention after 10,000 cycles. As a result, multi-element doping significantly enhances capacitive performance, including higher capacitance, improved rate capability, and excellent cycling stability. This work provides mechanistic insights into synergistic metal-heteroatom interactions and offers a scalable strategy for designing sustainable carbon-based electrodes for advanced energy storage systems. Overall, the results confirm that dual Mo-P modification effectively tunes electronic structure, enhances surface redox activity, and enables fast ion transport, making the material highly promising for next-generation high-energy and high-power supercapacitors. It offers practical potential for scalable energy storage applications.