Solar-driven water splitting is an appealing strategy to produce hydrogen energy. However, the non-negligible chance of reverse reactions due to a mixture of hydrogen molecules (H2) with oxygen species poses challenges for safe H2 collection and delivery, which hinders its applications. Using first-principles simulations, we propose a hybrid structure design where metal clusters of TM4 (TM = Au/Pt) are encapsulated in boron-carbon-nitride nanotube (BCNNT) decorated with CuN3 group. It can readily absorb ultraviolet-visible solar light to generate charge carriers. The energetic electrons and holes would be separately delivered to the reduction site of TM4 and the oxidation site of the BCNNT layer. Then, protons generated by water dissociation at the BCNNT layer will penetrate through BCNNT and consequently meet electrons at the TM4 site to be reduced into H2. As a selective sieve, BCNNT prevents oxygen species from going inside and H2 from crossing out so that H2 can be completely isolated. Further, the sufficient space of the tubular cavity endows the transportation feasibility of the produced H2 along the nanotube for collection. This proposed design combines photocatalytic hydrogen production and safe delivery, which may help in developing a practical solution for a photodriven hydrogen production.
Keywords: boron−carbon−nitride nanotube; hydrogen delivery; hydrogen production; metal clusters; photocatalytic water splitting.