Tightly Connected Poly(3-Thiophene Boronic Acid)/g-C₃N₄ Heterojunctions for Enhanced Visible-Light Photocatalytic Hydrogen Production

Constructing efficient polymer semiconductor/g-C3N4 heterojunctions is highly desirable for enhancing the photogenerated charge separation of g-C3N4 and further improving the solarhydrogen production efficiency. Herein, we synthesized poly(3thiophene boronic acid)/g-C3N4 (PTBA/CN) heterojunctions with tight interface contact by a simple wet-chemical strategy. The resulting ratio-optimized 3PTBA/CN heterojunction exhibits 8.7 times enhancement of the visible-light photocatalytic hydrogen production compared to CN. Based on the steady-state surface photovoltage spectra (SS-SPS), photoluminescence spectra (PL), *OH amount measurements, time-resolved photoluminescence spectra (TR-PL), and single-wavelength photocurrent action spectra, it is confirmed that the enhanced photocatalytic performance is mainly attributed to the promoted photogenerated charge separation resulting from the transfer of high-level electrons from CN to PTBA via the formed tight interface contact, depending on the hydrogen bonding interactions between the boronic acid groups [ B(OH)(2)] of PTBA and the amino groups ( NH2) of CN. Furthermore, the B(OH)(2) of PTBA facilitates the uniform dispersion of the co-catalyst Pt. This work provides an effective strategy for constructing efficient tightly connected polymer semiconductor/CN heterojunction photocatalysis.