Super hydrophilic-electrons acceptor regulated rutile TiO2 nanorods for promoting photocatalytic H-2 evolution

Photocatalytic H-2 evolution from water splitting in liquid-solid two-phase requires an efficient photocatalyst with excellent ability of charge separation and reactant molecular diffusion. In this study, the super hydrophilicelectrons acceptor with abundant -C=O and -OH functional groups were evenly grafted onto rutile TiO2 nanorods surface to speed up the charge separation and water molecular diffusion, respectively. The photocatalytic results showed that the TiO2-CA grafted by citric acid (with three -C=O, three carboxy-(-OH) and one alcohol-(-OH)) presented a 1.48. contact angle and a distinct increased H-2-production activity (48.5 mmol center dot h(-1)center dot g(-1)), whereas the TiO2-PA grafted by propane-1,2,3-tricarboxylic acid (Just lack of one alcohol-(-OH) compared with TiO2-CA) showed a 30.95 degrees contact angle and a decreased H-2-production activity (19.3 mmol center dot h(-1)center dot g(-1)) compared to the unmodified TiO2 (25.8 mmol center dot h(-1)center dot g(-1)), indicating that the super hydrophilicelectrons acceptor is vitally important to the photocatalytic activity of TiO2. Based on the present results, the carbonyl group (-C=O) possess a stronger reducing capability and act as "electrons acceptor", while the only alcohol-hydroxyl group (-OH) in TiO2-CA can decrease the mass transfer resistance and serve as "super hydrophilic absorber". Considering its mild preparation, inexpensive cost, and admirable efficiency, the super hydrophilic-electrons acceptor with dual functional groups regulated TiO2 can become a promising way for potential application in photocatalytic field.