Photocatalytic activity of graphene oxide incorporated pure and selected post-transition metal doped zinc oxide nanorods were investigated for the degradation of methylene blue dye. Thin film seed layers were deposited on microscopic glass slides using an automated spray pyrolysis technique at a substrate temperature of 425 °C. Aluminium, gallium, and indium were the metals used for doping. Graphene oxide content in the precursor solution was fixed at 0.00375 g/L. Nanorods of the aforesaid transparent conducting oxide materials were grown by aqueous chemical growth technique, vertically over the respective as-deposited seed layers. Structural and optical properties of the nanorods were studied. Growth of the vertical nanorods was confirmed by scanning electron microscopy. All the nanorod samples were utilized as catalysts for repeated cycles of photocatalysis and the graphene oxide incorporated indium doped zinc oxide nanorod was found to be an efficient and stable photocatalyst by degrading 96.1 % of methylene blue dye in 180 min under simulated solar irradiation. (https://doi.org/10.1016/j.ceramint.2023.12.221)

Piezoelectric materials capable of generating an inherent electric field under strain, exhibit promising applications in in-situ piezocatalysis and enhanced photocatalytic activities. SrTiO3 (STO) is a photocatalytic material, but it faces challenges such as low efficiency in photogenerated carrier separation and transfer, as well as limited reduction and oxidation reactions. To address these issues, this study utilized the piezoelectric properties of tetragonal BaTiO3 (BTO) nanoparticles and the photocatalytic properties of STO to prepare BaTiO3/SrTiO3 composite materials for piezoelectric assisted photocatalytic degradation of dyes. Disperse BTO nanoparticles with different mass ratios in STO spinning solution to produce a suspension, which is electrospun to form BTO-STO-1:x. The optimal degradation performance and catalytic activity of BTO-STO-1:x were determined through testing to identify the best composite material. It provides a robust foundation for underpinning the coupling mechanism between the enhancement of piezoelectricity and photocatalytic effect, offering an efficient pathway for advancing the field of piezoelectric assisted photocatalysis. (https://doi.org/10.1016/j.ceramint.2024.06.299)

Title: Mesoporous and macroporous Ag-doped Co3O4 nanosheets and their superior photo-catalytic properties under solar light irradiation
Abstract: An ideal photocatalyst should have a wider absorption capacity, a larger surface area, a narrow optical band gap, a better electronic conductivity, a lower load transfer resistance and a minimum charge recombination probability. Herein, mesoporous and macroporous nanosheets of Ag·Co3O4 have been synthesized via a two-step hydrothermal and post-annealing approach. The catalytic activities of the doped and undoped Co3O4 samples were tested and compared using Methylene Blue dye (MB) as a model pollutant. The specific surface area, optical band gap, electrical conductivity, and charge transfer resistance of the fabricated samples were analyzed using BET, UV/Visible, I–V, and EIS analyses. The Ag·Co3O4 sample showed a higher catalytic aptitude than the pristine Co3O4 sample because it degrades comparatively higher concentration of MB dye at a faster rate under natural sunlight irradiation. Specifically, the Ag·Co3O4 sample eliminated 88.4% MB dye at the rate constant (k) of 2.1 × 10−2 min−1 in only 90 min of solar irradiation. The outstanding removal efficiency and higher rate performance of the Ag·Co3O4 sample is attributed to its novel bimodal-porous structure, higher surface area (258 m2 g-1), narrow bandgap (1.55 eV), good electrical conductivity (1.5 × 105 Sm−1) and smaller charge transfer resistance. The exceptional activity of the Ag·Co3O4 sample under solar irradiation reveal its greatest potential to eliminate toxic and harmful dyes from industrial effluents. (https://doi.org/10.1016/j.ceramint.2020.12.121)

Title: Porous titanium dioxide supported on glass microbubbles to prepare a low-density photocatalyst for AR1 degradation
Abstract: Low-density TiO2(C)/GB hollow powders were synthesized by loading anatase TiO2 onto glass microbubbles. CTAB (cetyltrimethyl ammonium bromide) was used to produce pores in the supported TiO2. A TiO2 layer with a thickness greater than 100 nm was tightly loaded onto the glass microbubbles. CTAB led to a slight expansion of the bandgap energy from 3.22 eV (TiO2(0)/GB) to 3.41 eV (TiO2(3.0)/GB). The ECB and the EVB values were −0.32 and 2.91 V for the TiO2(1.5)/GB, respectively. Both the average pore size (from 5.59 to 9.44 nm) and the total pore volume (from 0.0799 to 0.1283 cm3/g) of TiO2(C)/GB increased with an increasing amount of CTAB. The hole-electron recombination efficiency was in the sequence of TiO2(1.5)/GB< TiO2(3.0)/GB< TiO2(0)/GB. The AR1 degradation efficiency varied with the CTAB amount, and the maximum degradation efficiency was obtained for TiO2(1.5)/GB. The TiO2(C)/GB hollow powders were suspended in an AR1 solution during the degradation process, and TiO2(C)/GB floated on the water surface after treatment to ensure fast solid-water separation. The reaction rate constants were 1.79 × 10−2 and 1.21 × 10−2 min−1 for TiO2(1.5)/GB and the unsupported TiO2 powders, respectively. TiO2(1.5)/GB had a stronger activity than the TiO2 powders. (https://doi.org/10.1016/j.ceramint.2021.05.117)