Enhanced hydrogen evolution rates at high pH with a colloidal cadmium sulphide–platinum hybrid system

Abstract

We demonstrate enhanced hydrogen generation rates at high pH using colloidal cadmium sulphide nanorods decorated with Pt nanoparticles. We introduce a simplified procedure for the decoration and subsequent hydrogen generation, reducing both the number of working steps and the materials costs. Different Pt precursor concentrations were tested to reveal the optimal conditions for the efficient hydrogen evolution. A sharp increase in hydrogen evolution rates was measured at pH 13 and above, a condition at which the surface charge transfer was efficiently mediated by the formation of hydroxyl radicals and further consumption by the sacrificial triethanolamine hole scavenger.

The Role of Cocatalysts on Bismuth Vanadate in the Abatement of Endocrine Disrupting Chemicals and Related Compounds under Visible Light

“…In principle, higher Pt loading is beneficial for the cocatalytic electron transfer by virtue of more available surface active sites. However, we observe an optimum activity at 2% Pt, suggesting that the effect may be limited by the formation of charge recombination centers, an effect commonly observed when depositing at too high metal loadings . At the optimum 2% Pt loading, the BPA was completely degraded after 2 h (Figure a), and as much as 74% of the total organic carbon (TOC) was mineralized (Figure b).…”

Mn(ii)-doped CdS/ZnS core/shell quantum dot films photocatalyze reductive organic transformations with a boost in efficiency from enhanced Auger processes

“…The ionic hole scavengers such as S 2− /SO 3 2− may be more compatible in aqueous media and yield more favourable kinetics. 40,52–54 We note that although microscopic changes on the QD surface were detected after 1 run, the decrease in reactivity was detected only after 3 runs (72 h of irradiation). Overall, the model reaction of stilbene production shows that doped QDs have superior photocatalytic activity compared with undoped QDs and may serve as replacements for transition metal complexes.…”

Rich Landscape of Colloidal Semiconductor–Metal Hybrid Nanostructures: Synthesis, Synergetic Characteristics, and Emerging Applications

“…• / OH − ), which follows Nernstian dependence (59 mV per pH unit), crosses and exceeds the energy level of the semiconductor VB, which has a weaker pH dependence (33 mV per pH unit), therefore promoting the reduction of holes via fast and efficient hydroxyl shuttle agents which now dominate the photocatalytic process. Such pH dependence was observed for CdS−Pt NRs as well, showing a steady increase of H 2 evolution rates upon increasing the pH values from pH 12 (3.6 mmol h −1 g −1 ) to pH 13 (21.8 mmol h −1 g −1 ) 257. Similarly, CdS−Pt NPLs61 and CdSe/CdS−Pt 239 NRs were also used to demonstrate the advantage of high alkaline conditions (Figure…”