Bi-ligand-fabricated CdS quantum dots to photo-induce aqueous-phase aldol condensation for biomass-derived carbonyl compounds

CdS QDs were fabricated using bi-ligands 11-sulfanylundecanoic acid and proline for photo-induced aqueous-phase aldol condensation of biomass-derived furfural compounds and ketones, and they displayed acceptable selectivity, activity and recycling properties for generation of a wide range of products with diverse applications. This work facilitates understanding the molecular-level design concepts of semiconductor photocatalysts.

Synergistic Trimetallic Nanocomposites as Visible-NIR-Sunlight-Driven Photocatalysts for Efficient Artificial Photosynthesis

Here, we report monodispersed tricomponent MnNSs-SnO2@Pt and MnNFs-SnO2@Pt nanocomposites prepared by simultaneous SnO2 and Pt nanodot coating on Mn nanospheres (MnNSs) and Mn nanoflowers (MnNFs) for highly efficient CO2 photoreduction in visible-NIR-sunlight irradiation. MnNFs-SnO2@Pt showed higher efficiency with a quantum yield of 3.21% and a chemical yield of 5.45% for CO2 conversion under visible light irradiation for HCOOH formation with 94% selectivity. Similarly, MnNFs-SnO2@Pt displayed significant photocatalytic efficiency in NIR and sunlight irradiation for HCOOH yield. MnNFs-SnO2@Pt nanocomposites also showed robust morphology and sustained structural stability with shelf-life for at least 1 year and were utilized for at least 10 reaction cycles without losing significant photocatalytic efficiency. The high surface area (94.98 m2/g), efficient electron-hole separation, and Pt-nanodot support in MnNFs--SnO2@Pt contributed to a higher photocatalytic efficacy toward CO2 reduction.

A Hybrid Assembly with Nickel Poly-Pyridine Polymer on CdS Quantum Dots for Photo-Reducing CO2 into Syngas with Controlled H2 /CO Ratios

A hybrid photocatalytic assembly with Ni poly-pyridine polymers binding on CdS quantum dots was developed via thiophene immobilization. The fabricated hybrid assembly facilitated efficient charge separation, and each component endowed great synergy. As a result, a high syngas production rate was achieved over 5500 μmol g_cat ^-1  h^-1 from photocatalytic CO₂ reduction under visible-light irradiation, accompanied by an adjustable H₂ /CO ratio ranging from 4 : 1 to 1 : 3. A novel hybrid assembly was described for syngas synthesis with boosted activity and controlled selectivity, which provides a profile to ingeniously understand molecular-level design for photocatalysts.

Morphology-Governed Performance of Multi-Dimensional Photocatalysts for Hydrogen Generation

In the past few decades, extensive studies have been performed to utilize the solar energy for photocatalytic water splitting; however, up to the present, the overall efficiencies reported in the literature are still unsatisfactory for commercialization. The crucial element of this challenging concept is the proper selection and design of photocatalytic material to enable significant extension of practical application perspectives. One of the important features in describing photocatalysts, although underestimated, is particle morphology. Accordingly, this review presents the advances achieved in the design of photocatalysts that are dedicated to hydrogen generation, with an emphasis on the particle morphology and its potential correlation with the overall reaction performance. The novel concept of this work—with the content presented in a clear and logical way—is based on the division into five parts according to dimensional arrangement groups of 0D, 1D, 2D, 3D, and combined systems. In this regard, it has been shown that the consideration of the discussed aspects, focusing on different types of particle morphology and their correlation with the system’s efficiency, could be a promising route for accelerating the development of photocatalytic materials oriented for solar-driven hydrogen generation. Finally, concluding remarks (additionally including the problems connected with experiments) and potential future directions of particle morphology-based design of photocatalysts for hydrogen production systems have been presented.

Visible-Light-Mediated Oxidative Amidation of Aldehydes by Using Magnetic CdS Quantum Dots as a Photocatalyst

A magnetic CdS quantum dot (Fe₃ O₄ /polydopamine (PDA)/CdS) was synthesized through a facile and convenient method from inexpensive starting materials. Characterization of the prepared catalyst was performed by means of FTIR spectroscopy, XRD, SEM, TEM, energy-dispersive X-ray spectroscopy, and vibrating-sample magnetometer techniques. Fe₃ O₄ /PDA/CdS was found to be a highly active photocatalyst for the amidation of aromatic aldehydes by using air as a clean oxidant under mild conditions. The photocatalyst can be recovered by magnetic separation and successfully reused for five cycles without considerable loss of its catalytic activity.