Phosphorus doped molybdenum disulfide regulated by sodium chloride for advanced supercapacitor electrodes.

As a pseudocapacitor electrode material, molybdenum disulfide (MoS 2 ) usually shows inferior capacity, rate capability and cyclability. Structural regulation and heteroatom doping are the available methods to ameliorate the electrochemical properties of MoS 2 . Herein, phosphorus doped molybdenum disulfide regulated by sodium chloride (SP-MoS 2 ) is successfully synthesized using phosphomolybdate acid as a molybdenum source and an in situ dopant and sodium chloride (NaCl) as a structural regulator. Under the structural regulation of NaCl, the SP-MoS 2 nanosheets exhibit an interweaved architecture with a large interlayer spacing of 0.68 nm. Owing to the in situ P doping and large specific surface area (21.0 m 2 g -1 ), the SP-MoS 2 electrode possesses a maximum capacity of 564.8 F g -1 at 1 A g -1 and retains 56.3% of the original capacity at 20 A g -1 . Density functional theory (DFT) calculations indicate that SP-MoS 2 displays a high K + average adsorption energy of -3.636 eV. In addition, the fabricated SP-MoS 2 //AC asymmetric supercapacitor device displays an energy density of 22.8 W h kg -1 at 759 W kg -1 .