Acid-Exfoliated Metallic Co_0.85Se Nanosheets as Cocatalyst on Cd_0.5Zn_0.5S for Photocatalytic Hydrogen Evolution under Visible-Light Irradiation

Abstract

Co 0.85 Se, nonstoichiometric phase, as an excellent electrocatalytic activity, was used as a cocatalyst to modify Cd 0.5 Zn 0.5 S nano-photocatalyst. The Co 0.85 Se (1.5 wt %)/Cd 0.5 Zn 0.5 S Schottky junction shows the greatest activity for H 2 generation (759.3 μmol h −1 ), which is 2.1 times that of bare Cd 0.5 Zn 0.5 S (350.6 μmol h −1 ). It turns out that Co 0.85 Se nanoplates can be exfoliated into nanosheets by diluted hydrochloric acid. It is noted that exfoliated metallic Co 0.85 Se nanosheets show a little better hydrogen evolution reaction property and a smaller charge-transfer resistance than those of Co 0.85 Se nanoplates, implying that exfoliated Co 0.85 Se nanosheets have more active sites and higher electrical conductivity. The distinct properties of exfoliated metallic Co 0.85 Se nanosheets enhance the efficient spatial separation of photoinduced charged particle carriers and result in an excellent enhancement in the photoelectric current and photocatalytic hydrogen evolution performance of Cd 0.5 Zn 0.5 S. The amount of Co 0.85 Se in the heterojunction has an obvious effect on the hydrogen evolution property. The consequences show that 1.5 wt % exfoliated Co 0.85 Se nanosheets added into the Cd 0.5 Zn 0.5 S sample result in the maximum water splitting rate of 759.3 μmol h −1 . For other semiconductor photocatalyst systems, our work demonstrates that introducing exfoliated metallic Co 0.85 Se nanosheets electrocatalyst as an efficient cocatalyst to improve photocatalytic capacity without noble metals is feasible.

Co0.85Se magnetic nanoparticles supported on carbon nanotubes as catalyst for hydrogen evolution reaction

“…3(a), the 2p3/2 peak deconvoluted into Co 3+ 2p3/2, Co 2+ 2p3/2, and shakeup satellite peaks. The peaks at 785.9 and 802.8 eV are ascribed to the shakeup satellite peaks, respectively, which is consistent with the findings of a previous report [15]. The peaks with binding energies of 781.4 and 797.5 eV correspond to Co 2+ and that at 778.2 eV corresponds to Co 3+ [33].…”

“…In recent years, low-cost earth-abundant transition metal compounds have been developed as possible alternatives, such as NiS2/MoS2 [7][8][9], CoP@ZnFeP [10], CoNi2S4 [11], and CoxNi1-xO [12]. Non-stoichiometric-phase cobalt selenide (Co0.85Se), an important metal chalcogenide, has received extensive attention owing to its excellent performance in a variety of applications such as in the fields of dye-sensitized solar cells [13], potassium-ion batteries [14], water splitting [1,15,16], and CO2 photo-reduction [17]. Interestingly, Co0.85Se and its ternary compounds, having a weak ferromagnetic property, are usually used for wastewater treatment [18,19].…”

Surface‐Activated Ti3C2TxMXene Cocatalyst Assembled with CdZnS‐Formed 0D/2D CdZnS/Ti3C2‐A40Schottky Heterojunction for Enhanced Photocatalytic Hydrogen Evolution

“…For CZS/Ti 3 C 2 ‐A 40 , The Raman peaks at 315 and 625 cm −1 are allocated to the one longitudinal optical (LO) and 2 LO phonon peaks of CZS, respectively. [ 37 ] The strong vibration peak around 120 cm −1 is attributed to the stacking of the flake of CZS/Ti 3 C 2 ‐A 40 .…”

Bridging electrocatalyst and cocatalyst studies for solar hydrogen production via water splitting

“…5c). [87][88][89][90][91][92][93][94] However, this technique is not viable for bulk oxide-based PCs (e.g., SrTiO 3 ) which require high-temperature (>800 C) solid-state synthetic reactions that can lead to CC decomposition.…”