Synergistic Electric Metal (Ni SAs)‐Semiconductor (CdS NPs) Interaction for Improved H₂O‐to‐H₂ Conversion Performance under Simulated Sunlight

Abstract

Single‐atom (SA) cocatalysis has obvious superiority in promoting solar‐to‐chemical energy conversion. However, easy aggregation of SAs is very unfavorable to its catalysis for high surface energy. Herein, a photoreduction procedure is adopted to immobilize Ni SAs on CdS nanoparticles (NPs) to construct the synergistic electric metal–semiconductor interaction (EMSI) for highly promoting the simulated sunlight‐driven H2O‐to‐H2 (HTH) conversion in alkaline condition (pH = 14.0) without any sacrificial agent addition, and the nanocatalyst with 1.25‰ of Ni carrying capacity (CdS–Ni1.25‰) achieves the highest HTH conversion rate (8149.71 μmol h−1 g−1, 13.0‐fold greater of that of CdS NPs) and stable photostability accompanied by 27.60% of apparent quantum yield (AQY400 nm). Characterizations and density functional theory calculations indicate that the EMSI on CdS–Ni1.25‰ nanocatalyst greatly improves the light absorption capacity and promotes the orderly bulk‐to‐surface migration of photoexcitons, effectively suppressing their recombination kinetics for higher photoexciton utilization efficiency. Under alkaline conditions, high concentration of OH− ions is easy to react with photogenerated holes to generate hydroxyl radicals for effectively inhibiting the oxidation half‐reaction and obtaining higher HTH conversion performance due to significantly reduced energy barriers on atomic Ni sites. This study provides an insight for improving the performance of a conventional photocatalyst through non‐noble metallic SAs cocatalysis.

0.68% of solar-to-hydrogen efficiency and super-high photostability: Panel H2O-to-H2 conversion based on a novel organic-inorganic membrane catalyst

“…Obviously, the CdS@SiO2 composite still appears nanorod-like morphology with smooth surface and increased transverse size, and the lattice fringes of d = 0.32 nm in Figure 2f are assigned to the (101) crystal plane of hexagonal CdS. 25 After SiO2 coverage, a nanolayer with a thickness of ~4.86 nm can be clearly observed from inset of Figure 2b, which can be identified as SiO2 nanolayer according to the energy dispersive X-ray (EDX) mappings in Figure 2h, forming a typical core-shell nanorod structure. As shown in Figure 1c, compared with the bare CdS NRs (0.84 mmol•g -1 •h -1 ), a slight decrease of SSL-driven HTH rate (0.84 → 0.63 mmol•g -1 •h -1 ) is presented on CdS@SiO2 NRs, which ascribes to the inactive character of SiO2 nanolayer in HTH conversion.…”

“…The CdS NRs were hydrothermally synthesized by following our previous protocol, 25 and the detailed procedure is given in Supplementary Information. The CdS@SiO2 NRs were prepared by coating a SiO2 nanolayer on the surface of CdS NRs via a sol-gel method (Figure 1a).…”

Bi/BiOI/carbon quantum dots nano-sheets with superior photocatalysis

“…26 Photoluminescence (PL) intensity of photocatalysts is capable of characterizing the recombination efficiency of photogenerated e − and h + . 51 As is known, weaker intensity represents lower efficiency of e − and h + recombination. 26 As shown in Fig.…”

Solar‐Driven Hydrogen Evolution with Superior Efficiency by a Low‐Cost, Large‐Scale Synergetic Hybrid of 1D‐Si Nanowires/0D‐Au Nanoparticles/2D‐MoS2 Nanofilms

“…[3] Currently, the photocatalytic hydrogen evolution reaction (PC-HER) in the process of water splitting is considered to be of lowest process cost and most clean method by which to convert solar energy into a storable form of energy. [4][5][6] For use in PC-HER, recently 2D MoS 2 has gained appreciable attention as a promising photocatalyst, based on two major reasons. One is that 2D MoS 2 turns out to be a direct-bandgap material, [7] in particular, that its bandgap can be tuned from 1.2 to 1.9 eV [7,8] to fit in the solar spectrum region; the other appears that 2D-MoS 2 presents high surface-area-to-volume ratio and a high density of active sites.…”