Advanced Oxidation technologies (AOTs) are gaining attention as an effective waste water treatment methodology capable of degrading diverse spectrum of recalcitrant organic contaminants and microbes. Undoubtedly, photocatalysis is a promising AOT to alleviate the problem of water pollution. Despite recent research into other photocatalysts (e.g. ZnO, ZnS, Semiconductor-Graphene composites, perovskites, MoS2, WO3 and Fe2O3), titanium dioxide (TiO2) remains the most popular photocatalyst due to its low cost, nontoxicity and high oxidising ability. Moreover, titania photocatalysts can easily be immobilized on various surfaces and be scaled up for large scale water treatment. The current review aims to highlight recent advancements in photocatalytic AOTs with main emphasis on TiO2 photocatalysis. This review also discusses the use of TiO2 photocatalysis for water and waste treatment, treating contaminants of emerging concern (CECs), pesticides, endocrine disrupters (EDs) and bacteria using both UV and visible light irradiations. It was concluded that with efficient photoreactor configuration and further studies on the photocatalyst regeneration, TiO2 photocatalysis is a viable option for the reclamation of agricultural/irrigational waste water. Novel doped photocatalysts such as ZnS-CuS-CdS, carbon spheres/CdS, g-C3N4-Au-CdS, ZnS-WS2-CdS, C3N4-CdS and Pd-Cr2O3-CdS have also been discussed. Finally, the advances in the actively studied metal organic framework based photocatalysts that are emerging as effective alternate for metal oxide based photocatalysts is also discussed in detail.

Recent advances in photocatalysis for environmental applications

Photocatalytic degradation of ciprofloxacin by a novel Z-scheme CeO2–Ag/AgBr photocatalyst: Influencing factors, possible degradation pathways, and mechanism insight

In this work, we design and construct a novel 2D/2D g-C 3 N 4 nanosheet@ZnIn 2 S 4 nanoleaf via a simple one-step surfactant-assisted solvothermal method for photocatalytic H 2 generation. Its unusual 2D/2D heterojunction structure provides far more contact areas and much faster charge transport rate than the 2D/0D heterojunction structure of g-C 3 N 4 nanosheet@ZnIn 2 S 4 microsphere. More importantly, this unique 2D/2D heterojunction leads the g-C 3 N 4 nanosheet@ZnIn 2 S 4 nanoleaf composite to generate numerous intimate high-speed charge transfer nanochannels in the interfacial junctions, and which could considerably enhance the photogenerated charge separation and migration efficiency, thus yielding a remarkable visible-light-driven H 2 evolution rate without the additive Pt cocatalyst (HER = 2.78 mmol h −1  g −1 ), nearly 69.5, 15.4, 8.2 and 1.9 times higher than that of pure g-C 3 N 4 nanosheet, pure ZnIn 2 S 4 microsphere, 2D/0D g-C 3 N 4 nanosheet@ZnIn 2 S 4 microsphere and pure ZnIn 2 S 4 nanoleaf, respectively. Additionally, the 2D/2D g-C 3 N 4 nanosheet@ZnIn 2 S 4 nanoleaf exhibits an outstanding stability and recyclability, manifesting a promising potential application in sustainable energy conversion. This work would provide a platform for the design and synthesis of binary heterojunction composite system with highly-efficient charge separation and transfer.

Preparation of 2D/2D g-C3N4 nanosheet@ZnIn2S4 nanoleaf heterojunctions with well-designed high-speed charge transfer nanochannels towards high-efficiency photocatalytic hydrogen evolution

Recent advances in transition-metal dichalcogenides based electrochemical biosensors: A review

A critical review on visible-light-response CeO2-based photocatalysts with enhanced photooxidation of organic pollutants

Fabrication of highly efficient visible light driven Ag/CeO2 photocatalyst for degradation of organic pollutants

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.

Rational design of a novel LaFeO3/g-C3N4/BiFeO3 double Z-scheme structure: Photocatalytic performance for antibiotic degradation and mechanistic insight

SnO2 photocatalyst was successfully synthesised by novel chemical route in hydrothermal environment and annealed at two different temperatures viz 550 and 600 °C, respectively. The crystal structure, optical properties, surface and bulk morphology have been characterised using various tools like X-ray diffraction (XRD), UV visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscope (TEM) and scanning electron microscope (SEM). Cubic, spheres and porous like morphology of SnO2 photocatalyst was successfully confirmed using SEM micrographs and TEM. In addition to this the photocatalytic activity was evaluated towards the degradation of methylene blue dye solution. SnO2 photocatalyst annealed at 600 °C exhibits excellent photocatalytic efficiency which may be attributed to the unique morphology, high crystalline nature and charge separation. The photocatalyst efficiency was further tested towards the concentration of dye, catalyst dosage and pH of the dye. The invo...

K. Saravanakumar

Papers

Fabrication of highly efficient visible light driven Ag/CeO2 photocatalyst for degradation of organic pollutants

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

Rational design of a novel LaFeO3/g-C3N4/BiFeO3 double Z-scheme structure: Photocatalytic performance for antibiotic degradation and mechanistic insight

Controllable synthesis of SnO2photocatalyst with superior photocatalytic activity for the degradation of methylene blue dye solution

Catalytic oxidation of naproxen in cobalt spinel ferrite decorated Ti3C2Tx MXene activated persulfate system: Mechanisms and pathways