Optimally Miscible Polymer Bulk-Heterojunction-Particles for Nonsurfactant Photocatalytic Hydrogen Evolution.

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Traditional mini-emulsion and nanoprecipitation methods for bulk-heterojunction-particles (BHJP) are limited by high surfactant use and poor miscibility of donor/acceptor materials.
• Surfactants can negatively impact BHJP performance by hindering electron transfer and polaron formation.

Purpose of the Study:

• To develop a surfactant-free precipitation method for fabricating highly miscible BHJP.
• To investigate the impact of surfactants on BHJP properties and performance.
• To enhance the hydrogen evolution rate (HER) of BHJP materials.

Main Methods:

• Molecular design of donor (PS) and acceptor (PSOS) polymers for optimal miscibility.
• Development of a novel surfactant-free precipitation technique.
• Characterization using multiscale experiments, molecular dynamics simulations, and transient absorption spectroscopy.

Main Results:

• Successfully fabricated the most miscible BHJP to date with excellent structural compatibility between PS and PSOS.
• BHJP particles (approx. 12 nm) self-assemble into cross-linked fractal networks (hundreds of nanometers).
• BHJP facilitates polaron formation and electron transfer, leading to a superior HER of 251.2 mmol h⁻¹ g⁻¹ and 26.2% apparent quantum yield at 500 nm.

Conclusions:

• The surfactant-free method offers a practical approach for preparing advanced BHJP.
• Eliminating surfactants enhances BHJP efficiency for applications like hydrogen evolution.
• This work provides a new avenue for designing high-performance heterojunction materials.