In this work, we report the fabrication of binary semiconductor heterojunctions comprising of N-doped ZnO nanorods loaded with two-dimensional MoS 2 nanoflowers in varying amounts, using a facile hydrothermal synthesis method. These semiconductor heterojunctions have been demonstrated as highly efficient photocatalysts with enhanced performance under visible light irradiation for the degradation of a pharmaceutical pollutant, tetracycline. The superior photocatalytic activity of the heterojunctions can be attributed to the synergistic effect of Ndoping of ZnO and loading of MoS 2 leading to higher absorption of visible light, efficient separation of photo generated charge carriers and rapid charge transfer to reaction sites, as per the conduction band potentials of both N-doped ZnO and MoS 2 . In addition, the twodimensional nanoflower morphology of MoS 2 provides more reaction sites for the adsorption of pollutant, due to its large surface area. Furthermore, the transfer of holes from the valence band of N-doped ZnO to the valence band of MoS 2 prevents the photocorrosion of N-doped ZnO resulting in enhanced photostability of the catalyst during the reaction.

Utilization of the total solar spectrum efficiently for photocatalysis has remained a huge challenge for a long time. However, designing a system by rationally combining nanocomponents with complementary properties, such as upconversion nanoparticles, semiconductors, plasmonic metals, and carbonaceous support, offers a promising route for efficient utilization of solar energy by harnessing the broadband spectrum. In this work, a series of novel quaternary plasmonic photocatalysts comprising of lanthanide-doped NaYF@CdS (UC) core-shell nanostructures decorated with Au nanoparticles (Au NPs) supported on reduced graphene oxide (RGO) nanosheets were prepared using the multistep hydrothermal method. The different components of the prepared nanocomposites could be efficiently employed to utilize both the visible and near-infrared (NIR) regions. Specifically in this work, the utility of these quaternary nanocomposites for photocatalytic degradation of a colorless pharmaceutical pollutant, ciprofloxacin, under visible and NIR light irradiations has been demonstrated. In comparison to bare counterparts, our quaternary nanocomposites exhibit an enhanced photocatalytic activity attributable to the synergistic effect of different components arranged in such a way that favors harnessing energy from the broad spectral region and efficient charge separation. The combination of upconversion and plasmonic properties along with the advantages of a carbonaceous support can provide new physical insights for further development of photocatalysts, which could utilize the broadband spectrum.

Novel RGO–NCT composites have been synthesized and utilized for the degradation of MB and TBZ, as efficient bifunctional adsorptive photocatalysts.

In this work, we report on the synergetic role played by MoS2–RGO doping in enhancing the photocatalytic activity of ZnO nanoparticles, especially in utilizing both the UV and the visible light regions of the solar spectrum.

In the pursuit towards the use of sunlight as a sustainable source for energy generation and environmental remediation, photocatalytic water splitting and photocatalytic pollutant degradation have recently gained significant importance. Research in this field is aimed at solving the global energy crisis and environmental issues in an ecologically-friendly way by using two of the most abundant natural resources, namely sunlight and water. Over the past few years, carbon-based nanocomposites, particularly graphene and graphitic carbon nitride, have attracted much attention as interesting materials in this field. Due to their unique chemical and physical properties, carbon-based nanocomposites have made a substantial contribution towards the generation of clean, renewable and viable forms of energy from light-based water splitting and pollutant removal. This review article provides a comprehensive overview of the recent research progress in the field of energy generation and environmental remediation using two-dimensional carbon-based nanocomposites. It begins with a brief introduction to the field, basic principles of photocatalytic water splitting for energy generation and environmental remediation, followed by the properties of carbon-based nanocomposites. Then, the development of various graphene-based nanocomposites for the above-mentioned applications is presented, wherein graphene plays different roles, including electron acceptor/transporter, cocatalyst, photocatalyst and photosensitizer. Subsequently, the development of different graphitic carbon nitride-based nanocomposites as photocatalysts for energy and environmental applications is discussed in detail. This review concludes by highlighting the advantages and challenges involved in the use of two-dimensional carbon-based nanocomposites for photocatalysis. Finally, the future perspectives of research in this field are also briefly mentioned.