Hydrogen gas (H2) is an important resource that has been gaining significant attention due to its use as a carbon-free fuel. However, the main methods of H2 production currently use fossil fuels, resulting in significant release of carbon dioxide. A possible cost-effective, green alternative is photocatalytic H2 evolution using nanoparticles of organic semiconductors. In this work, however, we present a novel approach of using the triplet exciton to potentially increase the efficiency of H2 evolution. Typically, this process uses light to generate a singlet excited state (exciton), which then undergoes charge separation at interfaces between an electron donor and acceptor material. Triplet excitons are long-lived species due to their spin-forbidden relaxation to the ground state. As a result, exciton dissociation to free charge carriers in the organic semiconductor may be enhanced due to the long excited-state lifetime. The use of triplets could pave the way for singlet fission, a process that converts a singlet into two triplets, to be explored for maximising the efficiency of H2 evolution in organic semiconductors.