NiSe₂ as Co‐Catalyst with CdS: Nanocomposites for High‐Performance Photodriven Hydrogen Evolution under Visible‐Light Irradiation

Abstract

One‐dimensional NiSe2/CdS nanocomposites (NCs), with NiSe2 nanoparticles (NPs) integrated onto the surface of CdS nanowires (NWs) were designed and fabricated through a two‐step in situ solvothermal method. Density functional theory (DFT) calculations showed that NiSe2 plays an important role in enhancing photocatalystic hydrogen (H2) production when coupled with CdS catalyst, which arises from 1) the contribution of Ni 3d and Se 4p orbitals to the electronic structures and 2) the charge redistribution at the interface region of the heterostructure results in efficient promotion of the charge transfer and separation of the photogenerated electron‐hole pairs. Under visible‐light illumination (λ≥400 nm), the NCs showed improved photocatalytic H2‐generation activity in the presence of lactic acid. The peak value of 7610.1 μmol h−1 g−1 for H2 production was achieved with an apparent quantum efficiency (AQE) of 41.68 % when the Ni/Cd ratio was set to 10 %, which was approximately 48 times higher than that of bare CdS NWs. Photoelectrochemical measurements also confirmed the pivotal role of NiSe2 in the improvement of the H2‐evolution performance of NiSe2/CdS NCs, which is consistent with the DFT investigations.

Photocatalytic Mechanism Control and Study of Carrier Dynamics in CdS@C3N5 Core–Shell Nanowires

“…It is worth mentioning that there exist much larger voids in the C 3 N 5 molecular framework compared to g-C 3 N 4 , 3 which may prevent strong interaction between atoms of different systems constituting the heterojunctions. Similar to previous reports, 93,94 these figures show that the valence band (VB) maximum of CdS is mostly made of S 3p orbitals, while the conduction band (CB) minimum is composed predominantly of Cd 5s orbitals, with minor contributions from S 3s and S 3p. These figures also reveal that the DFT-calculated band gap of CdS is lower than the experimentally found band gap (Figure S33 in the Supporting Information).…”

Hierarchical 0D NiSe2/2D ZnIn2S4 Nanosheet‐Assembled Microflowers for Enhanced Photocatalytic Hydrogen Evolution

“…Especially, Ni‐based cocatalyst has attracted increasing interest due to their unique properties, including high earth abundance, excellent conductivity, and low cost. [ 30 ] For example, NiSe 2 has a large work function and metal‐like properties, [ 31 ] and exhibits superior conductivity which contributes to improving the electron transfer efficiency. In addition, the Se–Se bonds of NiSe 2 play a critical role in the striking H 2 ‐production activity and stability.…”

Controlling Spin–Orbit Coupling to Tailor Type-II Dirac Bands

“…This result strongly suggests that the SOC in NiTe 2– x Se x alloys can be effectively tuned by Se content ( x ), although 1 T -NiSe 2 is unstable. Note that NiSe 2 has a pyrite-like structure and crystallizes in the cubic T h 6 space group. − …”