A recyclable NP-CDs/TiO2/PAN photocatalytic nanofiber membrane for enhanced photothermal synergistic hydrogen evolution

Photothermal NP-CDs/TiO 2 enabled H 2 evolution in recoverable PAN membranes. • Recyclable NP-CDs/TiO 2 /PAN nanofiber membranes were electrospun. • NP-CDs broaden TiO 2 light absorption and enhance photothermal conversion. • TC-3/PAN retains 92.2% activity after seven cycles over 28 h. Photothermal synergistic catalysis holds great promise for solar hydrogen production. Nevertheless, the separation and recycling of powder photocatalysts remain critical challenges for practical implementation. In the present investigation, nitrogen-doped polydopamine-derived carbon dots (NP-CDs) with pronounced photothermal effects were introduced into a TiO 2 -based photocatalytic hydrogen evolution system. The resulting composites were further immobilized onto polyacrylonitrile (PAN) membranes via electrospinning to construct a recyclable NP-CDs/TiO 2 /PAN (TC-3/PAN) nanofiber membrane. The introduction of NP-CDs extended the optical response region of TiO 2 and substantially enhanced its photothermal conversion capability. The optimized TC-3/PAN membrane reached a temperature of 58.3 °C under illumination and achieved a hydrogen evolution rate of 4.66 mmol/m 2 /h, corresponding to an 8.8 times enhancement relative to pristine TiO 2 /PAN. Moreover, TC-3/PAN retained 92.2% of its initial activity after seven cycles over 28 h, demonstrating excellent stability and recyclability. These findings offer a practical route for developing recyclable membrane-based photothermal catalytic systems. Download: Download high-res image (560KB) Download: Download full-size image