Rational Construction of LaFeO3 Perovskite Nanoparticle-Modified TiO2 Nanotube Arrays for Visible-Light Driven Photocatalytic Activity

Synthesis and performance evaluation of S-scheme heterostructured LaFeO3/TiO2 photocatalyst for the efficient degradation of thiamethoxam

The application of perovskite lanthanum ferrite (LaFeO3) as a photocatalyst has shown significant potential in the removal of persistent organic and inorganic contaminants. In the present research, LaFeO3 and various composites consisting of LaFeO3 and TiO2 were prepared. The photocatalytic efficiency of the produced catalysts was assessed by measuring their effectiveness in degrading thiamethoxam, a pesticide belonging to the second generation of neonicotinoids. Experimental investigations were carried out to examine the impact of various factors on the degradation process, including variables like concentration of thiamethoxam, catalyst amount, and pH level. The produced catalysts were characterized by various techniques, including field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS). The highest degradation rates were observed when using the synthesized catalyst, 1% LaFeO3/TiO2 (LFTO1), under both UV-C and direct sunlight conditions. This performance outperformed TiO2 and bare LaFeO3. When exposed to ultraviolet (UV-C) radiation at an intensity of 15 W m-2 and under neutral pH conditions, LFTO1 achieved approximately 97% degradation, while under direct sunlight, the LFTO1 photocatalyst exhibited a degradation rate of 79% within a 120-min reaction period. The enhanced activity of LFTO1 could be attributed to its increased surface area, reduced bandgap, and lower electron-hole recombination. The investigation of reaction kinetics showed that the degradation of thiamethoxam followed a pseudo-first-order rate law. Furthermore, LFTO1 can be employed up to 5 times without experiencing any loss in its catalytic activity, thus confirming its long-term utility.

Rational Construction of MOF-Derived Porous ZnTiO3/TiO2 Heterostructured Photocatalysts with Remarkable Photocatalytic Performance

TiO2 has been widely used in photodegradation of pollutants, but it suffers from inferior photocatalytic performance under solar light illumination. Thus, novel porous ZnTiO3/TiO2 heterostructured photocatalysts are constructed by hydrothermal and carbonization techniques using ZIF-8 as a sacrificial template. After coating with TiO2, ZIF-8 nanocubes are selectively etched and subsequently coprecipitated with Ti ions during the hydrothermal process. Thereafter, the pores generated from carbonized ZIF-8 provide a large specific surface area and abundant active reaction sites for photocatalysis after annealing, producing stable ZnTiO3/TiO2 nanocomposites. Thus, porous ZnTiO3/TiO2 heterostructured photocatalysts exhibit excellent photocatalytic performance under solar light irradiation due to the boosted electron-hole separation/transfer. The kinetic constant of ZnTiO3/TiO2 nanocomposites (4.66 × 10-1 min-1) is almost 100 and 3.7 times higher than that of self-degradation (4.69 × 10-3 min-1) and TiO2 (1.27 × 10-1 min-1), respectively. This facile strategy provides a deep insight into synthesizing heterostructured photocatalysts with high efficiency in the field of environmental remediation.

Substantial enhancement in the photocatalytic degradation of organic/inorganic pollutants in water and photoelectrochemical activity using TiO2@Ag@LaFeO3 core–shell nanorods

Designing of novel and efficient TiO2@Ag@LaFeO3 core–shell nanorods towards advanced remediation of toxic ions/organic compounds and photoelectrochemical activity under simulated solar light is demonstrated.

Tuning nanotubular structures by templateless electropolymerization with thieno[3,4-b]thiophene-based monomers with different substituents and water content

Here, templateless electropolymerization is employed to produce nanotubular structures from various thieno[3,4-b]thiophene-based monomers that differ in substituent structure and size, as well as the linker connecting the thieno[3,4-b]thiophene core and substituent. The formation of densely packed vertically aligned are obtained from monomers with a pyrene substituent and when a significant amount of water (CH₂Cl₂ + H₂O) is included in the solvent. The geometrical parameters of the nanotubes are highly dependent on the electopolymerization method. A significant amount of air is trapped within the structure of the densely packed open nanotubes obtained with Qs = 100 mC cm^-2 causing an increase in water contact angle (θ_w) up to 82.6° (intermediate state between the Wenzel and the Cassie-Baxter state), and θ_w can become even more hydrophobic by further modifying the deposition method or the electrolyte.

Special Issue: “Thin Films for Energy Harvesting, Conversion, and Storage”

Efficient clean energy harvesting, conversion, and storage technologies are of immense importance for the sustainable development of human society. To this end, scientists have made significant advances in recent years regarding new materials and devices for improving the energy conversion efficiency for photovoltaics, thermoelectric generation, photoelectrochemical/electrolytic hydrogen generation, and rechargeable metal ion batteries. The aim of this Special Issue is to provide a platform for research scientists and engineers in these areas to demonstrate and exchange their latest research findings. This thematic topic undoubtedly represents an extremely important technological direction, covering materials processing, characterization, simulation, and performance evaluation of thin films used in energy harvesting, conversion, and storage.

Photoelectrochemical Water Splitting with p-Type Metal Oxide Semiconductor Photocathodes

Photoelectrochemical (PEC) water splitting is a promising way to produce clean and sustainable hydrogen fuel. Solar hydrogen production by using p-type metal oxide semiconductor photocathodes has not been studied as extensively as that with n-type metal oxide semiconductor photoanodes and p-type photovoltaic-grade non-oxide semiconductor photocathodes. Copper-based oxide photocathodes show relatively good conductivity, but suffer from instability in aqueous solution under illumination, whereas iron-based metal oxide photocathodes demonstrate more stable PEC performance but have problems in charge separation and transport. Herein, an overview of recent progress in p-type metal oxide-based photocathodes for PEC water reduction is provided. Although these materials have not been fully developed to reach their potential performance, the challenges involved have been identified and strategies to overcome these limitations have been proposed. Future research in this field should address these issues and challenges in addition to the discovery of new materials.