The development of highly efficient and low-cost approaches for catalytic hydrogen production from renewable energy is of tremendous importance for a truly sustainable hydrogen-based energy carrier in future life. Herein, the probability of utilizing solar light to product hydrogen from biomass derivative, glucose, was systematically demonstrated by using the periodically ordered TiO 2 nanotube arrays (TNTAs) assembled of Palladium quantum dots (Pd QDs), i.e. Pd QDs@ TNTAs as photoanode. The results showed that remarkably increased photocurrent density was obtained in the glucose solution compared to the pure KOH electrolyte over as-prepared photoelectrode, which indicated that the glucose could be faster oxidized than water oxidation, and thus could promote the hydrogen production on Pt cathode. The yield of hydrogen production from glucose oxidation reached as high as 164.8 μmol cm −1 over Pd QDs@TNTAs photoanode and Pt cathode system (denoted as Pd QDs@TNTAs/Pt) under the solar light irradiation for 6 h, which was about 15 times higher than that from pure water splitting. The superior hydrogen production performance could be attributed to the less endergonic process of the glucose oxidation than water, as well as the efficient synergistic photoelectrocatalytic (PEC) glucose oxidation over Pd QDs@TNTAs photoanode which possesses excellent photoelectrochemical performance and structure characteristics. Moreover, a probable mechanism for the PEC hydrogen production from biomass derivatives oxidation was proposed and discussed.
Jingtao Zhang,Mengwan Zhai,Xueying Wang,Shurui Liu,Lijuan Zhang,Xing Liu,Yao Geng,Xiaodong Sun,Bingkun Liu
In the present work, Ti 3+ -self-doped TiO 2 heterostructure photocatalysts were prepared by coupling with different additions of palladium quantum dots by means of deposition-reduction methodology. The electron paramagnetic resonance (EPR) analysis indicated the existence of Ti 3+ in synthesized samples. The transmission electron microscopy (TEM) images presented the modification of TiO 2-x nanoparticles by coupling with nano palladium. Photoluminescence (PL) results demonstrated the lowest charge carrier recombination rate in 5% Pd/TiO 2-x composites. Photocatalytic performances of photocatalysts were evaluated by degrading Tetracycline (TC) and inactivating Escherichia coli ( E. coli ) and Fusarium oxysporum f. sp. Vasinfectum ( Fov ) with the presence of visible light , in which an enhanced photocatalytic degradation and inactivation activity was found in all Pd coupled composites with the highest efficiency in 5% Pd/TiO 2-x . The improved photocatalytic activity of Pd/TiO 2-x was associated to the generation of more hydroxyl radicals (•OH) and superoxide anions radicals (•O 2- ) during photocatalytic process which were demonstrated by the electron spin-resonance spectroscopy (ESR) technique. Moreover, 5% Pd/TiO 2-x composites were found to remain high photocatalytic properties in a circulating photo-disinfection system.