A Novel Earth‐Abundant W‐WC Heterojunction as Efficient Co‐Catalyst for Enhanced Photocatalytic H₂ Evolution

Abstract

New functional materials are of significance for the industry development of coal and tungsten. Here, we reported a novel earth‐abundant W‐WC heterojunction on CdS as an efficient and cheap co‐catalyst for photocatalytic H2 evolution on CdS under visible light irradiation. The W‐WC is simply synthesized from industrial raw material of coal and ammonium tungstate by a simple one‐step calcination strategy. The photocatalytic activities tests show that W‐WC heterojunction has better co‐catalytic performance than W or WC alone, and the optimal photocatalytic activity of W‐WC/CdS reaches 3314 μmol/h/g, which are17.4 and 2.6 times larger than that of CdS and Pt/CdS alone, respectively. Electrochemical tests demonstrate the WC has large specific capacitance and acts as electron reservoir storing the photo‐excited electron from CdS, whereas W mainly acts as the catalytic center. The heterojunction formed between W and WC is favorable for the electron transferring. The different functions of W and WC along with the heterojunction between W and WC account for the superiority of W‐WC. The design and fabrication strategy of the W‐WC heterojunction co‐catalyst benefits for the industrial development of new material and photocatalysis.

Construction of NiPx/MoS2/NiS/CdS composite to promote photocatalytic H2 production from glucose solution

“…With NiS, MoS 2 , and NiP x gradually modifying, the PL strength of samples is generally decreased (Figure 6C), illuminating that the recombination rate of photoexcited charge carriers is reduced. 23 Thus, the charge carriers of NiP x /MoS 2 / NiS/CdS composite perform much higher separation rate than that of other catalysts.…”

“…Additionally, the separation efficiency of charge carriers is further analyzed by photoluminescence (PL) spectroscopy and time‐resolved PL decay technology. With NiS, MoS 2 , and NiP x gradually modifying, the PL strength of samples is generally decreased (Figure 6C), illuminating that the recombination rate of photoexcited charge carriers is reduced 23 . Thus, the charge carriers of NiP x /MoS 2 /NiS/CdS composite perform much higher separation rate than that of other catalysts.…”

“…Meanwhile, heterostructure construction has been demonstrated to increase the photocatalytic activity by rapidly separating the electron–hole pairs. As a promising heterostructure, NiS/CdS composite has received much attention, and performs relatively high activity in photocatalytic H 2 evolution 23,24 . Additionally, cocatalyst deposition is another common strategy to facilitate the transfer of charge carriers, such as MoS 2 and NiP x , which are widely used to boost the photocatalytic H 2 production 25,26 .…”

“…As a promising heterostructure, NiS/CdS composite has received much attention, and performs relatively high activity in photocatalytic H 2 evolution. 23,24 Additionally, cocatalyst deposition is another common strategy to facilitate the transfer of charge carriers, such as MoS 2 and NiP x , which are widely used to boost the photocatalytic H 2 production. 25,26 The synergistic effects of heterostructure and multiple cocatalysts may effectively suppress the recombination of charge carriers and achieve high photocatalytic activity.…”

Robust Porous WC‐Based Self‐Supported Ceramic Electrodes for High Current Density Hydrogen Evolution Reaction

“…The XPS full‐spectrum (Figure S4, Supporting Information) shows the presence of the four elements of W, C, O, and N in the membrane. The W 4f spectral line can be deconvoluted into eight peaks (Figure 2e), which are attributed to the metallic tungsten (31.6 and 33.8 eV), [ 23 ] WC bonds (32.4 and 34.3 eV), [ 2a,24 ] WN bonds (35.3 and 37.6 eV), [ 19,22c ] and WO bonds (36.0 and 38.1 eV). The WO bonds should result from the inevitable WC surface oxidation.…”