Development of photocatalytic active SiCN-Ti e-spun fibers based on a polysilazane-derived precursor for hydrogen generation by photoreforming

This study focuses on synthesizing novel photocatalytic active Ti-doped SiCN fibers using a TiO₂ precursor (titanium n-butoxide) and a commercially available silazane (Durazane 1800). The Ti-doped SiCN fibers were processed by combining the polymer-derived ceramic route and the electrospinning technique, which consists of controlling the polymerization of the precursors, electrospinning of the solutions, followed by thermal crosslinking and pyrolysis in a controlled atmosphere. Spectroscopic assessments revealed that the TiO₂ precursor reacts with N-H and Si-H groups from the polysilazane during cross-linking. In addition, thermogravimetric analysis (TGA) essays showed that adding TiO₂ increased ceramic yield upon pyrolysis. Free carbon (C_free) and TiO₂ enhanced the target photoactivated processes by increasing the fiber's light absorption range. The composites displayed a bandgap within the visible-light region and exhibited a 4-fold increment in hydrogen (H₂) generation through photoreforming. The composites developed herein are promising candidates for visible-light-driven hydrogen generation systems.