P,Se‐Codoped MoS2 Nanosheets as Accelerated Electrocatalysts for Hydrogen Evolution

Abstract As the half reaction of water splitting, hydrogen evolution reaction (HER) is a prospective way to generate clean fuel of hydrogen. Molybdenum disulfide (MoS 2 ), as a member of the transition‐metal dichalcogenides, has attracted much research attention since its potential HER activity is predicted to be even comparable to Pt. However, the HER activity of MoS 2 is still far from desirable, owing to the high resistance and limited intrinsic active sites. Herein, we have successfully engineered MoS 2 by doping P and Se to regulate the electron density. The optimized P,Se‐MoS 2 /CNTs exhibit a low overpotential of 110 mV at 10 mA cm −2 and a small Tafel slope of 49 mV dec −1 , much better than P‐MoS 2 /CNTs, Se‐MoS 2 /CNTs, MoS 2 /CNTs, and closing to commercial Pt/C. The P,Se‐MoS 2 /CNTs also display excellent electrochemical stability over 15 days. Raman, XPS and surface valence band spectra confirm that P and Se codoping modulate the electron densities of the catalytic sites, which can largely improve the HER activity.