Synthesis of Ultra‐Small Palladium Nanoparticles Deposited on CdS Nanorods by Pulsed Laser Ablation in Liquid: Role of Metal Nanocrystal Size in the Photocatalytic Hydrogen Production

Abstract

It is imperative to suppress the rate of recombination of photogenerated carriers to improve the semiconductor-catalyzed solar-driven production of hydrogen. To this end, photocatalysts comprising active sunlight-harvesting photo-absorbers and stable metal co-catalysts have attracted significant attention. However, the size, clean surface, and highly dispersed nature of the metal co-catalysts are crucial factors affecting catalyst performance and reaction rate. Nevertheless, most of the available metal nanocrystals have been synthesized by complex procedures using harmful organic templates and stabilizers, affording high-purity compounds with difficulty and high cost. To overcome these problems, in this study, the pulsed laser ablation in liquid approach was utilized to generate palladium and bimetallic palladium-platinum nanoparticles with an average size and distribution by adjusting the laser wavelength and fluence. A high rate of evolution of hydrogen of 130.33 mmol g h was obtained by using the optimized CdS-PdPt catalyst under simulated sunlight irradiation. This value is 51.31 times greater than that observed for bare CdS nanostructures. Furthermore, the amount of hydrogen evolved was significantly better than that obtained by using several other noble-metal co-catalysts deposited on CdS. This proposed strategy is thought to open new avenues for the design of advanced photocatalytic materials for efficient solar-driven production of hydrogen.

Optimizing the precursor of sulfur source for hydrothermal synthesis of high performance CdS for photocatalytic hydrogen production

“…The band should be produced by the superposition of the band-edge emission (around 520 nm) and some shallow and deep trap-state-related emissions of CdS. 25,66 Usually a high PL intensity indicates a quick recombination rate of charge carriers and consequently leads to a low photocatalytic performance. But for a series of photocatalysts, this conclusion must be based on the same premise that the available number of e À and h + for the recombination process is comparable on these photocatalysts.…”

“…However, it should be noted that these manipulations and modications are essentially determined by the synthesis methods as the structure, grain size, morphology, and component of CdS-based photocatalyst are changed with the preparation conditions. [23][24][25][26][27] Thus, to pursue a high HER performance, the preparation route and the reaction conditions of CdS need to be optimized.…”

Visible‐Light Direct Conversion of Ethanol to 1,1‐Diethoxyethane and Hydrogen over a Non‐Precious Metal Photocatalyst

“…41‐1049) (Figure S3, Supporting Information). No obvious diffraction peaks were attributed to Ni‐MoS 2 in the XRD patterns and no significant diffraction peaks were different from those of the CdS nanorods after the co‐catalyst loaded, probably due to the relatively small amount of Ni‐MoS 2 distribution and too strong diffraction peaks of the CdS nanorods . In addition, we performed the synthesis of Ni‐MoS 2 without CdS nanorods addition, and the resulting XRD pattern unveiled that the nickel was doped in the MoS 2 , due to no obvious characteristic peaks of NiS (Figure S4, Supporting Information), which was in agreement with a previous report …”

Perovskite Oxide LaNiO3 Nanoparticles for Boosting H2 Evolution over Commercial CdS with Visible Light

“…[1][2][3][4][5] Semiconductor-mediated photocatalytic water splitting is one intriguing technique for producing clean hydrogen (H 2 ) energy. [6][7][8][9][10][11][12][13][14] Over the past few decades, metal oxides and metal sulfides,a sw ell as their desired hybrids, have been investigated extensively as activec atalysts for H 2 generation. [15][16][17][18][19][20][21][22] However,t he efficiency realized so far can stilln ot meet the needs of commercial utilization, which is hindered mainly by the scarcity of affordable, efficient, and stable photocatalysts.…”

“…The conversion of solar energy into chemical fuels has long been recognized as a promising strategy for the development of sustainable and renewable alternatives to fossil reserves . Semiconductor‐mediated photocatalytic water splitting is one intriguing technique for producing clean hydrogen (H 2 ) energy . Over the past few decades, metal oxides and metal sulfides, as well as their desired hybrids, have been investigated extensively as active catalysts for H 2 generation .…”