Palladium‐Modified TiO2/MWCNTs for Efficient Carbon Capture and Photocatalytic Reduction of Nitro‐aromatic Derivatives

Abstract

AbstractIn this study, modified TiO2 nanocomposites with the noble metal (Ag or Pd) followed by dispersion on multiwall carbon nanotubes (MWCNT) were synthesized and applied in the photocatalytic oxidation of CO at room temperature in the absence of oxygen. The results revealed that the highest active photocatalyst was Pd/TiO2/MWCNT towards CO and p‐nitrophenol (PNP) conversion. The reaction was dependent on the catalyst loading, concentration of tert‐butyl ammonium bromide (TBAB) as co‐catalyst and the reaction time as well as the temperature of their reduction. It was found that the optimal condition for PNP transformed into p‐aminophenol (PAP) and formic acid (HCOOH) was the use of 0.05 wt % of Pd/TiO2/MWCNT nanocatalyst, 2 mol % of TBAB under visible light irradiation condition at room temperature after 1 hour. The as‐prepared photocatalysts were fully characterized using Scanning electron microscope (SEM‐EDX), high resolution transmission electron microscope (HR‐TEM), X‐ray diffraction (XRD) and Brunauer‐Emmett‐Teller (BET). In addition, the band gaps of TiO2 nanoparticles, TiO2/MWCNT and Ag‐ or Pd‐modified TiO2/MWCNT nanocomposites were calculated from diffuse reflectance spectroscopic (DRS) analysis, ensuring the best photocatalytic efficiency. This approach is significantly beneficial for development of new generation of detoxification/transformation catalysts. The probable mechanism of photo‐oxidation of CO by H2O was postulated.