Cu-carbon hollow and solid sphere modified triphasic TiO2 for efficient H2 generation in deionized water and river water

Herein, utilizing cheap carbonated beverage (Fanta) as the carbon source, the multiphasic TiO 2 /Cu-C composites are successfully designed and prepared for efficient photocatalytic H 2 generation. Excitingly, the controllable preparation of triphasic, biphasic and rutile phase TiO 2 can be achieved by adjusting the reaction temperature. As expected, under ultraviolet–visible light irradiation, the triphasic TiO 2 /Cu-C-5 exhibited the best photocatalytic H 2 evolution rate (HER, 28.53 mmol g −1  h −1 ), which is about 21.45 and 1.65 times as high as than that of triphasic TiO 2 and P25/Cu-C-5, respectively. In addition, the HER reached 7.67, 12.47 and 3.46 mmol g −1  h −1 in Tianyi lake water, Ganjing river water and Bohai seawater, respectively. Furthermore, the experiment of inorganic salt ions effect on HPR shows that NO 3 − and SO 4 2 - ions have great negative influence. This transient photocurrent response, photoluminescence and photoluminescence lifetime experiments indicate that the carrier Cu-C and the construction of heterophase junctions are conducive to the separation of photogenerated charges and reducing their recombination efficiency, resulting in the improvement of the photocatalytic hydrogen evolution performance. Meanwhile, the Cu-C sample contains hollow spheres, which facilitate the refraction of light and enhance its absorption. These advantages strongly prove that the triphasic TiO 2 /Cu-C photocatalyst has potential application prospects in the field of catalytic hydrogen evolution in deionized water and natural water.