In Situ Preparation of CoP@CdS and Its Catalytic Activity toward Controlling Nitro Reduction under Visible-Light Irradiation

Abstract

CoP was synthesized in situ on the surface of CdS nanowires using a cobalt–ammine complex as a precursor. The generated CoP@CdS photocatalyst was well characterized by X-ray diffraction, transmission electron microscopy, selected-area electron diffraction, and diffuse reflectance spectra. A more efficient charge transfer was successfully achieved owing to the close contact between CoP and CdS. The hybrid photocatalyst showed excellent activity for the reduction of nitroarenes to the corresponding anilines or azobenzene compounds in water. In present work, hydrogen evolution and nitro reduction were concurrent and with the consumption of substrate, the rate of hydrogen evolution increased. The driving force for the reduction originated from the activated hydrogen species in the photocatalytic reaction rather than from dihydrogen. The photocatalytic activity of as-prepared CoP@CdS in situ is comparable to that of the catalysts formed using a noble metal loaded onto CdS. Mechanistic investigation showed that the condensation route is the major pathway for nitro reduction in the present system, and azo compounds could be obtained with less irradiation time, while aniline will be obtained via long-time irradiation.

Rapid Microwave‐Assisted Synthesis of CdS/Graphene/MoSx Tunable Heterojunctions and Their Application in Photocatalysis

“…Yet, there have been studies where t 50 was up to 6 min . In the remaining examples, the corresponding index ranged between 2 h and 17 h . In this work, t 50 was about 1 h. All the aforementioned data corroborate our notion that microwave‐assisted synthesis of hybrid catalytic systems may pave the way for the development of multifunctional materials.…”

“…Concerning the synthetic protocols of CdS‐based hybrids by conventional heating, only in two cases the duration time was 12 h in total . In the remaining examples, the total time of conventional heating processes towards the synthesis of hybrid photocatalyst ranged between 26 h and 51 h . In our microwave‐assisted process, the total reaction time was of 2 h and 10 min.…”

“…Due to the large amount of articles concerning the synthesis of hybrid catalytic systems by hydro(solvo)thermal process, we isolated eight cases, in which CdS‐based hybrids are used as photocatalysts for nitroarene reduction . Synthesis of neat CdS nanoparticles by conventional heating was performed within 24 h, whereas in our case, 10 min was the duration time. Concerning the synthetic protocols of CdS‐based hybrids by conventional heating, only in two cases the duration time was 12 h in total .…”

Metal Sulfide Photocatalysis: Visible‐Light‐Induced Organic Transformations

“…[77] The alkylation of amines and α-H of ketoneswith In-situ CoP@CdS was valuable in reduction of the nitro under visible-light irradiation (Scheme 23b) and its synthesis method is worthy of concern. [78] First, The preparation of CdS nanowires was executed from CdCl 2 · 2.5H 2 O and C 5 H 10 NNaS 2 · 3H 2 O. Second, Co(OAc) 2 · 4H 2 O aqueous solution was dropwise added into the mixture of as-prepared CdS nanowires, ethanol and water, followed by 0.5 mL of NH 3 · H 2 O, getting products of Co 3 O 4 @CdS.…”

Visible‐Light‐Driven Self‐Coupling of Methylarenes Catalyzed by Ni2P@Cd0.5Zn0.5S Nanoparticles

“…Our group has already reported CdS could effectively make nitroarene reduction into aniline . Similarly, Cd 0.5 Zn 0.5 S solid solution demonstrated high optical and excellent electronic properties and it had been applied in degradation of organic pollution .…”