Facile synthesis and defect optimization of 2D-layered MoS2 on TiO2 heterostructure for industrial effluent, wastewater treatments

Abstract

Current research is paying much attention to heterojunction nanostructures. Owing to its versatile characteristics such as stimulating morphology, affluent surface-oxygen-vacancies and chemical compositions for enhanced generation of reactive oxygen species. Herein, we report the hydrothermally synthesized TiO2@MoS2 heterojunction nanostructure for the effective production of photoinduced charge carriers to enhance the photocatalytic capability. XRD analysis illustrated the crystalline size of CTAB capped TiO2, MoS2@TiO2 and L-Cysteine capped MoS2@TiO2 as 12.6, 11.7 and 10.2 nm, respectively. The bandgap of the samples analyzed by UV–Visible spectroscopy are 3.57, 3.66 and 3.94 eV. PL spectra of anatase phase titania shows the peaks present at and above 400 nm are ascribed to the defects in the crystalline structure in the form of oxygen vacancies. HRTEM reveals the existence of hexagonal layered MoS2 formation on the spherical shaped TiO2 nanoparticles at the interface. X-ray photoelectron spectroscopy recommends the chemical interactions between MoS2 and TiO2, specifically, oxygen vacancies. In addition, the electrochemical impedance spectroscopy studies observed that L-MT sample performed low charge transfer resistance (336.7 Ω cm2) that promotes the migration of electrons and interfacial charge separation. The photocatalytic performance is evaluated by quantifying the rate of Congo red dye degradation under visible light irradiation, and the decomposition efficiency was found to be 97%. The electron trapping recombination and plausible photocatalytic mechanism are also explored, and the reported work could be an excellent complement for industrial wastewater treatment.

Co-assembled MoS2–TiO2 Inverse Opal Photocatalysts for Visible Light-Activated Pharmaceutical Photodegradation

“…This unique tunability together with the excellent electrical, optical, and mechanical properties of 2D MoS 2 underpinned its application potential beyond electronics and optoelectronics to photocatalytic and electrocatalytic H 2 evolution, as well as water-related environmental applications including organic adsorption and photocatalytic degradation, membrane separation, sensing, and disinfection. – Although the MoS 2 band edge positions can be tuned to redox potentials that allow the generation of reactive oxygen species (ROS), , the photocatalytic performance of standalone MoS 2 nanosheets is compromised by its relatively low oxidation potential to amply produce hydroxyl radicals and the abundance of stable, though chemically inert, basal planes that reduce the number of active catalytic sites stemming primarily from edges and S vacancies . Nanostructuring and heterojunction formation have been intensively pursued in order to alleviate these shortcomings by the deposition of MoS 2 nanosheets on nanostructured TiO 2 supports, including nanobelts, , nanotubes, , nanospheres, , facets, , and nanoparticles, , for the development of VLA MoS 2 –TiO 2 photocatalysts. A prominent example has been provided by the vertically oriented growth of MoS 2 nanosheets on TiO 2 nanorods, leading to the preferential exposure of the highly reactive edge sites that also reduce electron and hole diffusion lengths, promoting charge separation and overall catalytic reaction rates .…”

A Comparative Study of Nanostructures of CuO/Cu2O Fabricated via Potentiostatic and Galvanostatic Anodization

“…In this scenario, supercapacitors are emerging electrochemical energy storing devices due to its enormous properties like high power density, safe operational quality, fast charging/discharging rate, faster response time, long-term cycle stability and ecofriendliness [1][2][3][4][5][6][7][8]. Transition metal oxide/hydroxide such as CoO [9,10], RuO 2 [11], NiO [12,13], MgO, CuO [14][15][16][17][18], TiO 2 [19,20], and FeO [21,22] is the most commonly used electrode material in a electrochemical setup, and they determine the electrochemical performance of the supercapacitors [23]. Among these transition metal oxides, CuO is a multifunctional material, and it has versatile properties like inexpensiveness, low-toxicity, high theoretical capacity (670 mAhg −1 ), and low electrical conductivity [24][25][26].…”

Facile Synthesis of rGO/Mn3O4 Composite for Efficient Photodegradation of Phenol under Visible Light

“…These compounds have stubborn nonbiodegradable properties and toxicity and, therefore, posed to be fatally harmful to aquatic life and humans since the phenolic compounds own considerably high binding capacity in aqueous medium. Furthermore, their unpleasant odor and taste add to the detrimental effect on aqueous systems [7][8][9][10]. Thus, it is important to develop an adhesive-like material to remove the organic pollutants from water bodies to minimize pollution [11][12][13].…”