A wide range of inorganic nanostructures have been used as photocatalysts for generating H2. To increase activity, Z-scheme photocatalytic systems have been implemented that use multiple types of photoactive materials and electron mediators. Optimal catalysis has previously been obtained by interfacing different materials through aggregation or epitaxial nucleation, all of which lowers the accessible active surface area. DNA has now been used as a structure-directing agent to organize TiO2 and CdS nanocrystals. A significant increase in H2 production compared to CdS or TiO2 alone was thus observed directly in solution with no sacrificial donors or applied bias. The inclusion of benzoquinone (BQ) equidistant between the TiO2 and CdS through DNA assembly further increased H2 production. While the use of a second quinone in conjunction with BQ showed no more improvement, its location within the Z-scheme was found to strongly influence catalysis. TiO2 and CdS nanocrystals were organized into a Z-scheme photosynthesis system by using DNA as a structure-directing agent. Increased H2 production from water splitting was observed compared to either the photocatalyst alone or dispersed mixtures of the two. The inclusion of the electron mediator benzoquinone equidistant between the TiO2 and CdS through DNA assembly further increased H2 production.
- electron mediators
All Science Journal Classification (ASJC) codes