Controlling Performance of Organic Semiconductor Bulk Heterojunction Nanoparticle Photocatalysts for Solar-Driven Hydrogen Production
Kevin Sivula a
a Laboratory for Molecular Engineering of Optoelectronic Nanomaterials, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
Proceedings of MATSUS Fall 2025 Conference (MATSUSFall25)
E5 Emerging organic-based materials for Solar-driven fuel production - #EOSF
València, Spain, 2025 October 20th - 24th
Organizers: Soranyel Gonzalez Carrero and Filip Podjaski
Invited Speaker, Kevin Sivula, presentation 167
Publication date: 21st July 2025

The bulk heterojunction (BHJ) concept, which has been successfully developed for solution-processed organic semiconductor-based photovoltaic (OPV) devices, offers a promising route to high-performance, scalable, and inexpensive photocatalyst nanoparticles (NPs) for solar-driven hydrogen production. However, state of the art BHJ NPs exhibit quantum yields far below OPVs, thus understanding how NPs characteristics affect their performance is a major goal. Herein we present insights to NP formation and co-catalyst deposition that demonstrate the effect of NP size and co-catalyst morphology on the performance of PTB7-Th:ITIC BHJ NPs. Specifically, using the emulsion NP preparation route, we report how BHJ NP size influences photocatalytic H2 evolution, with a drastic increase in H2 production when reducing NP diameter from 230 nm to 25 nm. Moreover, we introduce a halted photodeposition-dialysis method that affords unprecedented control over platinum (Pt) co-catalyst loading and morphology. Applying this method with typical Pt deposition conditions gave a max H2 evolution rate of 140 mmol h−1 g−1 (based on semiconductor mass) with only 15.2 wt % Pt and suggested an optimum loading of < 20 wt % Pt, above which parasitic light absorption decreases the H2 evolution rate.

© FUNDACIO DE LA COMUNITAT VALENCIANA SCITO
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info