Construction and characterization of visible light active Pd nano-crystallite decorated and C-N-S-co-doped TiO sub(2) nanosheet array photoelectrode for enhanced photocatalytic degradation of acetylsalicylic acid

A photo-assisted deposition technique was adopted to construct highly dispersed Pd nano-crystallites on C-N-S-co-doped TiO sub(2) nanosheets (Pd/C-N-S-TiO sub(2) NS) arrays photoelectrodes prepared by one-step hydrothermal synthesis. The morphology, elemental composition, crystal structure, light absorption capability and photoelectrochemical (PECH) property of as-obtained Pd/C-N-S-TiO sub(2) NS electrodes were determined and investigated through the various characterizations. The photocatalytic (PC) and photoelectrocatalytic (PEC) activity of the Pd/C-N-S-TiO sub(2) NS electrode was evaluated through the degradation of acetylsalicylic acid and the formation of radical dot OH radicals. Compared with pristine TiO sub(2) NS, Pd/TiO sub(2) NS and C-N-S-TiO sub(2) NS, Pd/C-N-S-TiO sub(2) NS electrode displayed greatly enhanced PC and PEC activity towards the degradation of acetylsalicylic acid under visible light ( lambda > 420 nm) or Xenon light irradiation. The synergy effect of interfacial transfer of photoinduced electrons between Pd nanoparticles and TiO sub(2) NS as well as the external potential and intense visible light absorption induced by C, N and S co-doing promoted the effective charge separation and transfer and more visible photons to participate in the catalytic process on obtained Pd/C-N-S-TiO sub(2) NS, which were evidenced by a series of characterizations, resulting in highly efficient and stable PC and PEC activity. Moreover, the probable visible light PEC mechanism was proposed.