Tungsten-Modulated Molybdenum Selenide/Graphene Heterostructure as an Advanced Electrode for All-Solid-State Supercapacitors
Qixian Liu, Jing Ning, Haibin Guo, Maoyang Xia, Boyu Wang, Xinliang Feng, Dong Wang, Jincheng Zhang, Yue Hao
Abstract
Transition metal dichalcogenides (TMDs) have attracted widespread attention due to their excellent electrochemical and catalytic properties. In this work, a tungsten (W)-modulated molybdenum selenide (MoSe2)/graphene heterostructure was investigated for application in electrochemistry. MoSe2/graphene heterojunctions with low-doped W compositions were synthesized by a one-step hydrothermal catalysis approach. Based on the conducted density functional theory (DFT) calculations, it was determined that inserting a small amount of W (≈5%) into the MoSe2/graphene heterostructure resulted in the modification of its lattice structure. Additionally, an increase in the distance between layers (≈8%) and a decrease in the adsorption energy of the potassium ions (K+) (≈−1.08 eV) were observed following W doping. Overall, the electrochemical performance of the MoSe2/graphene hybrid was enhanced by the presence of W. An all-solid-state supercapacitor device prepared using electrodes based on the W-doped MoSe2/graphene composite achieved excellent capacitance of 444.4 mF cm−2 at 1 mV s−1. The results obtained herein revealed that the MoSe2/graphene hybrid exhibiting low W composition could be valuable in the field of energy storage and isoelectronic doping of TMDs.