Z-scheme Si/MgTiO3 porous heterostructures: Noble metal and sacrificial agent free photocatalytic hydrogen evolution

• Without any of the sacrificial agent and noble metal.
• This work is probably the first time to use Si/MgTiO3 as photocatalyst.
• This work will replenish the investigation of titanate on photocatalysis.
• Photocatalyst has high catalytic activity and excellent stability.

Fabricating Z-scheme photocatalysts is an important strategy for improving the conduction-band edge, reducing the valance-band edge and speeding the separation of photogenerated electrons and holes, which is attracting more attention. In our study, Si/MgTiO3 heterostructures were synthesized by Mg thermal reduction of SiO2/TiO2 composites and HF-treatment. Through combination of these two materials (Si, MgTiO3) with non-ideal band structure for photocatalytic water splitting, the Si/MgTiO3 heterostructures performed a decent H2 generation from pure water without any sacrificial agents and shown excellent stability under visible light irradiation. Moreover, this is the first study to report the MgTiO3 as host photocatalyst. Through this artificial modulation of band structure can turn impossible into possible.