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

Abstract Constructing efficient polymer semiconductor/g‐C 3 N 4 heterojunctions is highly desirable for enhancing the photogenerated charge separation of g‐C 3 N 4 and further improving the solar‐hydrogen production efficiency. Herein, we synthesized poly(3‐thiophene boronic acid)/g‐C 3 N 4 (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 (−NH 2 ) 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.