Research PaperTowards enhancing photocatalytic hydrogen generation: Which is more important, alloy synergistic effect or plasmonic effect?

- Catalysts composed of Pt, Au and C3N4 were developed for water splitting.
- Pt50Au50/C3N4 showed remarkable turnover frequency at room temperature.
- Physical insights were gained by comparing synergistic to plasmonic effects.
- Synergistic effect contributes much more than plasmonic effect to photocatalysis.
- It represents the first case study of both effects in water splitting.

Synergistic effect in alloys and plasmonic effect have both been explored for increasing the efficiency of water splitting. In depth understanding and comparison of their respective contributions in certain promising systems is highly desired for catalyst development, yet rarely investigated so far. We report herein our thorough investigations on a series of highly interesting nanocomposites composed of Pt, Au and C3N4 nanocomponents, which are designed to benefit from both synergistic and plasmonic effects. Detailed analyses led to an important conclusion that the contribution from the synergistic effect was at least 3.5 times that from the plasmonic effect in the best performing sample, Pt50Au50 alloy decorated C3N4. It showed remarkable turnover frequency of >1.6 mmol h−1 g−1 at room temperature. Our work provides physical insights for catalyst development by rationally designing samples to compare long-known synergistic effect with recently emerging, attractive plasmonic effect and represents the first case study in the field.

175Our work represents the first case study in the field and answers an important, yet not previously addressed question: synergistic and plasmonic effect, which can make more important contribution in a promising catalysis system? It also provides guides for developing highly efficient and economic photocatalysts in general; combination of plasmonic metal nanoparticles with synergistic alloy nanoparticles based on lower cost metals can be a very promising future research direction.