The paper reviews the state of the art in the synthesis of multinary (ternary, quaternary and more complex) metal chalcogenide nanocrystals (NCs) and their applications as a light absorbing or an auxiliary component of light-harvesting systems. This includes solid-state and liquid-junction solar cells and photocatalytic/photoelectrochemical systems designed for the conversion of solar light into the electric current or the accumulation of solar energy in the form of products of various chemical reactions. The review discusses general aspects of the light absorption and photophysical properties of multinary metal chalcogenide NCs, the modern state of the synthetic strategies applied to produce the multinary metal chalcogenide NCs and related nanoheterostructures, and recent achievements in the metal chalcogenide NC-based solar cells and the photocatalytic/photoelectrochemical systems. The review is concluded by an outlook with a critical discussion of the most promising ways and challenging aspects of further progress in the metal chalcogenide NC-based solar photovoltaics and photochemistry.

Solar light harvesting with multinary metal chalcogenide nanocrystals

Controlled structural and compositional characteristic of visible light active ZnO/CuO photocatalyst for the degradation of organic pollutant

In this study, we report a series of novel palladium nanoparticles (Pd) supported cerium oxide (CeO2)/graphitic carbon nitride (g-C3N4) nanocomposites, fabricated via the simple strategy, which were used for the detoxification of toxic hexavalent chromium to benign trivalent chromium under visible light irradiation The synthesized Pd/CeO2/g-C3N4 nanocomposites were characterized by various tools including powder X-ray diffraction (PXRD), fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS/UV-vis), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectra (EDS) The wrapping with surface of graphitic carbon nitride nanosheets can efficiently promote the interface charge separation and transmission over the ternary photocatalyst, which was studied by photoluminescence spectra (PL) analysis and electrochemical impedance spectroscopy (EIS) spectra The obtained 3% Pd/CeO2/g-C3N4 nanocomposite photocatalyst exhibit an excellent photocatalytic performance when compared to other single and composite counter parts The 3% Pd/CeO2/g-C3N4 exhibits a strong synergistic effect which arises due to the interactions between palladium nanoparticles, CeO2 and graphitic carbon nitride resulting in the lower recombination of photo-induced charge carriers with enhanced photocatalytic activity This work implies that the synergistic Pd/CeO2/g-C3N4 nanocomposites would be a new kind of high-efficiency visible-light-driven photocatalysts materials for the detoxification of public safety and security

Construction of novel Pd/CeO2/g-C3N4 nanocomposites as efficient visible-light photocatalysts for hexavalent chromium detoxification.

Multifunctional ZnO nanorod-reduced graphene oxide hybrids nanocomposites for effective water remediation: Effective sunlight driven degradation of organic dyes and rapid heavy metal adsorption

The present work focuses on the surfactant mediated synthesis of ZnAl2O4 nanoparticles (1−3) using sol–gel method. 1 has been synthesized without any surfactant and during the synthesis of 2 and 3 cationic (cetyltrimethylammonium bromide) and anionic (sodium lauryl sulfate) surfactant, respectively, have been added. 1–3 have been characterized by P-XRD, FT-IR, SEM, SAED, TEM and BET techniques which suggest that surfactant reduces the particle size of ZnAl2O4 nanoparticles to half (12 nm in 1, 6 nm in 2 and 3). Zeta (ζ) potential measurements have been performed to determine the surface charges of all the samples. Moreover, the photocatalytic activities of these ZnAl2O4 nanoparticles have also been investigated. 2 exhibits better adsorption (28–41%) and degradation (97–99%) efficiency for anionic dyes due to high surface area (129.62 m2 g−1) and positively charged surface (ζ potential 30.06 mV). Radical trapping experiments suggest O2 − and OH to be the major reactive species for the degradation of dyes.

Facile synthesis of phase pure ZnAl 2 O 4 nanoparticles for effective photocatalytic degradation of organic dyes

Elimination of organic pollutants from wastewaters under visible-light irradiation is a venerable challenge in the fields of environmental and material science. In this work, we present a facile eco-friendly method to fabricate novel Cu2SnS3 flowers/RGO (Cu2SnS3/RGO) nanocomposites via a solvothermal method using L-cysteine as a sulphur source and linker. The crystal structure, morphology, purity, spectroscopic, and charge carrier separation properties of the synthesized samples were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission-scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and X-ray energy-dispersive spectroscopy (EDS), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and electrochemical impedance spectroscopy (EIS). The photocatalytic performance of the Cu2SnS3/RGO nanocomposites was evaluated by photocatalytic decolorization of eosin under visible-light irradiation. Results showed that the Cu2SnS3/RGO (3%) nanocomposite exhibits enhanced photocatalytic activity compared with the pure Cu2SnS3. The improved photocatalytic activity of the nanocomposite was mainly attributed to the formation of well-defined interface between Cu2SnS3 and graphene sheets, which greatly enhance the charge carrier separation efficiency in the Cu2SnS3 semiconductor.

A. Selvakumar

Papers

Biomolecule-assisted solvothermal synthesis of Cu2SnS3 flowers/RGO nanocomposites and their visible-light-driven photocatalytic activities