Fig. 6: In situ Raman and DFT calculations for HER mechanism.
From: Data-driven discovery of biaxially strained single atoms array for hydrogen production
a, b In situ Raman spectra for bMoSe2 and SAA Au-bMoSe2 in 0.5 M H2SO4 with continuously changed potentials from 0 to − 0.3 V vs. RHE. The dash arrows in (a, b) show the increase in potential. D and G denote the disorder and graphitic bands, respectively. The blue, gray, and green shadings highlight the Raman peaks of SO42-, D/G, and Se-H bonds, respectively. c Crystal orbital Hamilton population (COHP) analysis for Se-H bonds in MoSe2 (left) and Au atom anchored MoSe2 (right). d Scheme of SAA Au-bMoSe2 structure (left) and an active hotspot for HER (right). The red, blue, yellow, and white balls in (d) illustrate the Au, Mo, Se, and H atoms, respectively. The gray arrows show the movement direction of H. The strain along the x and y-directions in (d) are indicated by the green and red dash arrows, respectively. The color bar in (d) changing from blue to red qualitatively indicates the enhancement in HER activity, and the large gradient-colored ball covering Mo and Se atoms presents the active hotspot.
