In situ synthesis of C-doped TiO2@g-C3N4 core-shell hollow nanospheres with enhanced visible-light photocatalytic activity for H2 evolution

• C-doped TiO2@g-C3N4 (TCN) core-shell hollow nanospheres were prepared by an in situ method.
• TCN exhibits remarkably enhanced visible-light photocatalytic activity for water splitting.
• H2 generation rate of TCN is 22.7 and 10.5 times higher than C-TiO2 and g-C3N4, respectively.
• The intimate contact between two semiconductors was s realized by the in situ growth approach.
• The intimate contact greatly improved the separation and transfer efficiency of carries.

Developing photocatalysts with high charge separation and transfer efficiency remains a key challenge for photocatalytic water-splitting reaction. In this work, a facial approach was explored to successfully realize the in situ growth of g-C3N4 on the surface of C-doped TiO2 hollow nanospheres (C-TiO2). The as-obtained heterogeneous photocatalyst, C-TiO2@g-C3N4 (TCN), presented core-shell hollow nanosphere structure. Systematic studies disclose that the TCN photocatalysts exhibit remarkably enhanced visible-light photocatalytic activity for water splitting to produce H2 compared with the pristine C-TiO2 and g-C3N4. The TCN-2 photocatalyst (the weight ratio of initial urea and C-TiO2 is 2:1) presents the highest H2 generation rate of 35.6 μmol g−1 h−1, which is 22.7 and 10.5 times higher than that of C-TiO2 and g-C3N4, respectively. The enhanced photocatalytic performance can be attributed to the formation of the heterojunction between the two semiconductors, which effectively promotes the separation of photo-generated carriers. Meanwhile, the intimate contact between the C-TiO2 and g-C3N4 resulted from the in situ growth greatly improves the separation and transfer efficiency of photo-generated carries. Besides, the enhancement in the utilization efficiency of light energy due to the unique hollow structure also exhibits a positive contribution.

Figure optionsDownload high-quality image (98 K)Download as PowerPoint slide