Construction of highly dispersed Nd2O3 nanoparticles onto mesoporous LaNaTaO3 nanocomposites for H2 evolution

Coupling of Nd doping and oxygen-rich vacancy in CoMoO4@NiMoO4 nanoflowers toward advanced supercapacitors and photocatalytic degradation

In this paper, we successfully prepared rare earth element-doped 0.8% Nd-CoMoO4@NiMoO4 nanoflowers with a large specific surface area using the sol-gel method for the first time. In the experiment, we added a structure-directing agent to successfully assemble the nanosheets into a three-dimensional ordered micro-flower shape. By using the strategy of forming a flower-shaped morphology with a structure-directing agent and doping Nd elements to generate oxygen vacancies, the problems of the collapse of the active material structure and slow reaction kinetics were solved. Through relevant electrochemical performance tests, it was found that when the rare earth element Nd was doped at a concentration of 0.8%, the material exhibited exceptional specific capacitance (2387 F g-1 at 1 A g-1) and cycling stability (99.3% after 10 000 cycles at 5 A g-1). These performance characteristics far surpassed those of the other synthesized products. We assembled 0.8% Nd-CoMoO4@NiMoO4 with hydrophilic CNTs into an asymmetric device, 0.8% Nd-CoMoO4@NiMoO4//CNTs. This device exhibited high specific capacitance (262 F g-1 at 1 A g-1) and cycling stability (99.2% after 3000 cycles), with a good energy storage effect. In addition, 0.8% Nd-CoMoO4@NiMoO4 has a low band gap, which broadens the absorption range of the product and improves the utilization rate of visible light. The photocatalyst showed good degradation efficiency (all exceeding 96%) and cycling stability (96%) for all four dyes. This paper provides a new strategy and method for preparing doped polymetallic mixtures, which has potential application value.

Visible-light photooxidation of ciprofloxacin utilizing metal oxide incorporated sol-gel processed La-doped NaTaO3 nanoparticles: A comparative study

The supper dissemination of antibiotic waste in water resources has exponentially progressed the vital water and soil pollution that affect human health and the environment. Consequently, there have been several types of research anticipated for the green mineralization of such pollutants. Herein, we intended a surfactant-aided sol-gel formation of lanthanum-doped sodium tantalate (LNTO) nanocrystals. The synthesized 13 nm averaged-size perovskite LNTO nanocrystals were responsive to visible-light irradiation by incorporation of 4.4-5.2 nm oxide nanoparticles, namely Bi₂O₃, CdO, Fe₂O₃, and CuO at 4.0 wt% through coprecipitation. The formed nanomaterials unveiled mesostructured surface textures with specific surface areas of 199-229 m² g^-1. The obtained nanoceramics were employed for the mineralization of 10 ppm of ciprofloxacin antibiotic (CPF) as an emerging antibiotic waste in water under visible light irradiation. The CuO-incorporated LNTO exhibited the best photocatalytic oxidation of CPF after 120 min compared with other oxides with an excellent photoreaction rate of 0.0343 min^-1 which is 49 times higher than the pure LNTO. The 2.0 gL^-1 CuO/LNTO-dose achieved the full photooxidation of CPF at an oxidation speed of 0.0738 min ^-1 within just 1.0 h of visible light irradiation and magnificent regeneration ability. This enhanced activity of CuO/LNTO is regarded as significant light absorption and a bandgap energy reduction to 2.12 eV. Besides that, the heterojunction between CuO and LNTO amended the photogenerated carrier mobility and separation as concluded from the photoluminescence and photocurrent exploration. This comparative work suggests the proper design of low bandgap oxide decoration of solution-based perovskite oxide photocatalysts for promoting the visible-light mineralization of antibiotics in water.

Hydrogen Generation over RuO2 Nanoparticle-Decorated LaNaTaO3 Perovskite Photocatalysts under UV Exposure

The efficacy of LaNaTaO₃ perovskites decoration RuO₂ at diverse contents for the photocatalytic H₂ generation has been explored in this study. The photocatalytic performance of RuO₂ co-catalyst onto mesoporous LaNaTaO₃ was evaluated for H₂ under UV illumination. 3%RuO₂/LaNaTaO₃ perovskite photocatalyst revealed the highest photocatalytic H₂ generation performance, indicating that RuO₂ nanoparticles could promote the photocatalytic efficiency of LaNaTaO₃ perovskite significantly. The H₂ evolution rate of 3%RuO₂/LaNaTaO₃ perovskite is 11.6 and 1.3 times greater than that of bare LaNaTaO₃ perovskite employing either 10% CH₃OH or pure H₂O, respectively. Interestingly, the photonic efficiency of 3%RuO₂/LaNaTaO₃ perovskite was enhanced 10 times than LaNaTaO₃ perovskite in the presence of aqueous CH₃OH solutions as a hole sacrificial agent. The high separation of charge carriers is interpreted by the efficient hole capture using CH₃OH, hence leading to greater H₂ generation over RuO₂/LaNaTaO₃ perovskites. This is attributed to an adjustment position between recombination electron-hole pairs and also the reduction of potential conduction alignment as a result of RuO₂ incorporation. The suggested mechanisms of RuO₂/LaNaTaO₃ perovskites for H₂ generation employing either CH₃OH or pure H₂O were discussed. The photocatalytic performances of the perovskite photocatalyst were elucidated according to the PL intensity and the photocurrent response investigations.