Sequential Chemistry Toward Core–Shell Structured Metal Sulfides as Stable and Highly Efficient Visible‐Light Photocatalysts

Abstract

A universal sequential synthesis strategy in aqueous solution is presented for highly uniform core–shell structured photocatalysts, which consist of a metal sulfide light absorber core and a metal sulfide co‐catalyst shell. We show that the sequential chemistry can drive the formation of unique core–shell structures controlled by the constant of solubility product of metal sulfides. A variety of metal sulfide core–shell structures have been demonstrated, including CdS@CoSx, CdS@MnSx, CdS@NiSx, CdS@ZnSx, CuS@CdS, and more complexed CdS@ZnSx@CoSx. The obtained strawberry‐like CdS@CoSx core–shell structures exhibit a high photocatalytic H2 production activity of 3.92 mmol h−1 and an impressive apparent quantum efficiency of 67.3 % at 420 nm, which is much better than that of pure CdS nanoballs (0.28 mmol h−1), CdS/CoSx composites (0.57 mmol h−1), and 5 %wt Pt‐loaded CdS photocatalysts (1.84 mmol h−1).

A General Polymer‐Oriented Acid‐Mediated Self‐Assembly Approach toward Crystalline Mesoporous Metal Sulfides

“…The absorption edge of Zn x Cd 1−x S shows slight red shift with the increase of the Cd content, revealing bandgap narrowing. [47][48][49][50] To further elaborate the band structures of the samples, the valence band (VB) XPS spectra and Mott-Schottky plots were carried out to investigate the VB positions and conducting band (CB) positions, respectively. The VB values of as-prepared mesoporous ZnS-1.0, CdS, and Zn 0.56 Cd 0.44 S are 2.249, 1.429, and 1.427 eV corresponded to normal hydrogen electrode (NHE) (Figure 5a), through linear extrapolation on the leading edges of the VB spectra.…”

“…The Mott-Schottky plots show a positive slope (Figure 5b), indicating that these samples are typical n-type semiconductors. [34,48] Therefore, the flat band potential can be approximately equal to the CB level. According to the intercept of Mott-Schottky curves on the E axis, the CB for mesoporous ZnS-1.0, Zn 0.56 Cd 0.44 S, and CdS are determined to be about −1.233, −1.187, and −1.094 eV versus saturated calomel electrode (SCE) (−0.992, −0.946, and −0.853 eV versus NHE).…”

An All‐Organic D‐A System for Visible‐Light‐Driven Overall Water Splitting

“…Furthermore, Gibbs free energy change of H* adsorption (ΔG H *) is considered to be an important descriptor to evaluate the H 2 evolution performance, which is calculated by DFT calcula tions. [63][64][65] As shown in Figure 5f and Table S4 (Supporting Infor mation), for Bulk CN and TCN, the calculated ΔG H * values are −0.41 and −0.45 eV. Dramatically, after grafting carbon rings units into the basal plane of TCN, the ΔG H * value of CTCN is reduced to −0.25 eV, which is very close to that of Pt (−0.09 eV), indicating that the H 2 evolution reaction activity of CTCN is greatly pro moted.…”

Simultaneously Efficient Solar Light Harvesting and Charge Transfer of Hollow Octahedral Cu2S/CdS p–n Heterostructures for Remarkable Photocatalytic Hydrogen Generation

“…Photocatalytic water splitting has attracted tremendous attention as a catholicon to the worldwide energy dilemma, converting solar energy resources into clean oxygen and hydrogen fuels [2]. To date, a large number of semiconductors such as metal oxides, chalcogenides, nitrides, and oxynitrides have been widely employed as photocatalytic materials [3]. Specifically, metal chalcogenides exhibit great potential in the field of solar energy conversion [4].…”

“…Specifically, metal chalcogenides exhibit great potential in the field of solar energy conversion [4]. Among these semiconductor materials, due to various merits such as narrow bandgap and suitable band energy position, the n-type CdS is regarded as a prominent sulfide for solar energy conversion, particularly in solar hydrogen generation [3]. Meanwhile, the p-type copper sulfide is a good catalyst due to its relatively narrow bandgap and suitable band edge positions [3,4].…”