“…Chemical structures of MoS 2 , spent GC and CNF, and newly formed MoS 2 @CNF and MoS 2 @GC were studied by FT-IR for acquiring the stretching and bending vibrations of functional groups in the samples, as shown in Figure b. In the spectrum of MoS 2 , MoS 2 @CNF, and MoS 2 @GC, the perceptible peaks at 589, 880–960 cm –1 , and 1633–1637 cm –1 delineate the Mo–S, S–S, and Mo–O stretching vibrations, respectively, depicting the formation of MoS 2 . , In the spectrum of CNF and GC, the peak at 1198 cm –1 can be attributed to the stretching vibrations of the carboxylic group, which indicates the growth of carbon fibers and graphitic carbon on the spent catalyst, while the peak at 1400 cm –1 depicts the disarranged structure of the interlayered spent catalyst with O–H bend, which was further disordered by hydrothermal treatment, providing more surface area where MoS 2 can get deposited. , The adsorption band at 3445 cm –1 is associated with the stretching vibration of the hydroxyl (−OH) functional group, and the intensity of O–H stretching is reduced in the nanostructured electrocatalyst because more MoS 2 was formed. The hydrazine hydrate used in the synthesis process acted as a reducing agent, which removed the water molecules from the synthesized electrocatalyst, resulting in lowering of O–H transmittance.…”