CdIn₂S_4‐xSe_x Solid‐Solution Nanocrystal Photocatalyst: One‐Step Hydrothermal Synthesis, Controllable Band Structure, and Improved H₂‐Evolution Activity

Abstract

Metal sulfide solid‐solutions have served as one of the most promising photocatalysts due to continuously adjustable bandgap structure and light‐absorption performance. Herein, a novel quaternary CdIn2S4‐xSex solid‐solution nanocrystal photocatalyst is prepared by one‐step hydrothermal synthesis, including the initial production of CdIn2S4‐x(SeO3)x and its in situ reduction of SeO32− to produce Se2− by N2H4. It is found that the bandgap structure of CdIn2S4‐xSex nanocrystals can be adjusted from 2.42 to 1.87 eV by varying the molar ratio of Se/S. Compared with pure CdIn2S4, the CdIn2S4‐xSex solid‐solution photocatalyst clearly represents excellent photocatalytic hydrogen production performance, while the CdIn2S4‐xSex (x = 0.4) solid‐solution nanocrystal exhibits the optimal hydrogen‐production efficiency of 314.24 µmol h−1, which is 3.3 times superior to that of CdIn2S4 (94.83 µmol h−1). It is found that the introduction of Se increases the charge density of S2− to form electron‐enriched S(2+δ )−, which can promote the effective adsorption of H+ for the following interfacial hydrogen‐evolution reaction. Meanwhile, the CdIn2S4‐xSex solid‐solution nanocrystals have a higher conduction band and stronger visible‐light absorption ability, which is also essential for accelerating photocatalytic hydrogen‐production efficiency. This study may offer possibilities for developing high‐performance photocatalysts.

Optimizing nanoparticle attributes for enhanced anti-wear performance in nano-lubricants

“…Ethylenediamine works as a morphology control agent, preventing aggregation or precipitation and providing stability to metal complexes. It also eliminates the possibility of impurities or secondary phases [52,53]. The resultant liquid was then blended with hydrazine (N 2 H 4 ) to control the oxidation state.…”

Photodeposition of NiS Cocatalysts on g‐C3N4 with Edge Grafting of 4‐(1H‐Imidazol‐2‐yl) Benzoic Acid for Highly Elevated Photocatalytic H2 Evolution

“…Generally speaking, the more effective and desirable separation of charge carrier will show a smaller PL average lifetime. [31,68] And this figure could be precisely estimated by the equation.…”

Optimizing Oxygen and Intermediate HOO* Adsorption of Cu–Pd Alloy Cocatalyst for Boosting Photocatalytic H2O2 Production of BiVO4

“…Considering that Pd-based alloy is an effective strategy to mediate the O 2 adsorption energy on its surface and the corresponding theoretical calculation for the oxygen adsorption energy and HOO * binding energy on Pd-based alloy surfaces, in this paper, a bimetallic Cu-Pd alloy cocatalyst for the first time is selectively modified on the (010) facets of single-crystal BiVO 4 via selective photodeposition of low-cost Cu and followed in situ galvanic displacement of Cu by Pd. [42][43][44] In this case, the incorporation of Cu atoms into Pd atoms effectively weakens the oxygen adsorption energy and HOO * binding energy on Pd atom surfaces. As a result, the photocatalytic H 2 O 2 concentrations can reach 2189 µmol L -1 with apparent quantum efficiency (AQE) of 6.8% for Cu-Pd/BiVO 4 photocatalyst with the optimum Cu and Pd amounts, which is 3.2-fold higher than that of 675 µmol L -1 for BiVO 4 with modification of Pd cocatalyst (0.3 wt%).…”