Coupling Interface Constructions of MoS₂/Fe₅Ni₄S₈ Heterostructures for Efficient Electrochemical Water Splitting

Abstract

Water splitting is considered as a pollution-free and efficient solution to produce hydrogen energy. Low-cost and efficient electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) are needed. Recently, chemical vapor deposition is used as an effective approach to gain high-quality MoS nanosheets (NSs), which possess excellent performance for water splitting comparable to platinum. Herein, MoS NSs grown vertically on FeNi substrates are obtained with in situ growth of Fe Ni S (FNS) at the interface during the synthesis of MoS . The synthesized MoS /FNS/FeNi foam exhibits only 120 mV at 10 mA cm for HER and exceptionally low overpotential of 204 mV to attain the same current density for OER. Density functional theory calculations further reveal that the constructed coupling interface between MoS and FNS facilitates the absorption of H atoms and OH groups, consequently enhancing the performances of HER and OER. Such impressive performances herald that the unique structure provides an approach for designing advanced electrocatalysts.

Natural‐Cellulose‐Nanofibril‐Tailored NiFe Nanoparticles for Efficient Oxygen Evolution Reaction

“…As shown in Figure a, the average diameter of NiFeNSC was about 10–20 nm. HRTEM images reveal lattice spacings of 0.352, 0.354 and 0.503 nm, which are consistent with the Fe 5 Ni 4 S 8 (220) and (200) planes (Figure c and 3d) . The interplanar spacings of 0.280 and 0.286 nm were identical with those of Ni 3 S 2 (012) and (110) (Figure c), respectively, and the spacing of 0.206 nm was ascribed to the (111) plane of FeNi 3 (Figure e) .…”

Synergism of Interface and Electronic Effects: Bifunctional N‐Doped Ni3S2/N‐Doped MoS2 Hetero‐Nanowires for Efficient Electrocatalytic Overall Water Splitting

“…The metallic Ni signal at 852.9 eV originates from the NF substrate. For the spectrum of the Mo 3 d region (Figure b), three characteristic peaks, referring to Mo 3 d 3/2 (232.5 eV), Mo 3 d 5/2 (229.1 eV), and S 2 s (226.4 eV), can be observed . As displayed in Figure c, two characteristic peaks at 162.4 and 163.6 eV in the S 2 p XPS spectrum are well fitted with S 2 p 3/2 and S 2 p 1/2 , respectively.…”

Carbon Layer Coated Ni3S2/MoS2 Nanohybrids as Efficient Bifunctional Electrocatalysts for Overall Water Splitting

“…In addition, it is found that heterostructures from two transition metal sulfides can enhance the electrocatalytic performance in comparison to individual species, due to synergistic effects from the bimetallic active sites on the interfaces or enhanced electron transfer. For example, MoS 2 /Fe 5 Ni 4 S 8 /Ni foam, Co 9 S 8 @MoS 2 /carbon nanofibers, MoS 2 −Ni 3 S 2 /Ni foam, NiS 2 −MoS 2 nanoflakes/Ti foil, and oxygenated‐CoS 2 −MoS 2 /carbon fiber cloth, exhibit improved HER or OER catalytic activities relative to their individual nanostructures on the conductive scaffolds. The inclusion of conductive scaffolds offers a high surface‐area substrate guide for the in‐situ growth of heterostructure nanoarrays, and concomitantly allows a better electron/mass transfer during the electrochemical reactions .…”