Hydrogen and Propane Production From Butyric Acid Photoreforming Over Pt-TiO2

One-Step Synthesis of CuxOy/TiO2 Photocatalysts by Laser Pyrolysis for Selective Ethylene Production from Propionic Acid Degradation

In an effort to produce alkenes in an energy-saving way, this study presents for the first time a photocatalytic process that allows for the obtention of ethylene with high selectivity from propionic acid (PA) degradation. To this end, TiO₂ nanoparticles (NPs) modified with copper oxides (Cu_xO_y/TiO₂) were synthetised via laser pyrolysis. The atmosphere of synthesis (He or Ar) strongly affects the morphology of photocatalysts and therefore their selectivity towards hydrocarbons (C₂H₄, C₂H₆, C₄H₁₀) and H₂ products. Specifically, Cu_xO_y/TiO₂ elaborated under He environment presents highly dispersed copper species and favours the production of C₂H₆ and H₂. On the contrary, Cu_xO_y/TiO₂ synthetised under Ar involves copper oxides organised into distinct NPs of ~2 nm diameter and promotes C₂H₄ as the major hydrocarbon product, with selectivity, i.e., C₂H₄/CO₂ as high as 85% versus 1% obtained with pure TiO₂.

Synthesis and Photocatalytic Activity of Pt-Deposited TiO2 Nanotubes (TNT) for Rhodamine B Degradation

Dye wastewater has attracted more and more attention because of its high environmental risk. In this study, a novel TiO2 nanotube (TNT) catalyst was prepared and its morphology and structure were characterized. The synthetic catalyst was used to degrade Rhodamine B (RhB) under UV light and evaluated for the application performance. According to the characterization results and degradation properties, the optimum synthetic conditions were selected as 400°C calcination temperature and 10 wt% Pt deposition. As a result, the degradation efficacies were sequenced as TNT-400-Pt > TNT-500-Pt > TNT-400 > TNT-300-Pt. In addition, the effect of pH and initial concentration of RhB were explored, and their values were both increased with the decreased degradation efficacy. While the moderate volume of 11 mm of H2O2 addition owned better performance than that of 0, 6, and 15 mm. Scavengers such as tertbutanol (t-BuOH), disodium ethylenediaminetetraacetate (EDTA-Na2), and nitroblue tetrazolium (NBT) were added during the catalytic process and it proved that superoxide radical anions (O2–•), photogenerated hole (h+) and hydroxyl radical (OH•) were the main active species contributing for RhB removal. For the application, TNT-Pt could deal with almost 100% RhB, Orange G (OG), Methylene blue (MB), and Congo red (CR) within 70 min and still kept more than 50% RhB removal in the fifth recycling use. Therefore, TNT-Pt synthesized in this study is potential to be applied to the dye wastewater treatment.