Effect of Controlling Thiophene Rings on D-A Polymer Photocatalysts Accessed via Direct Arylation for Hydrogen Production

Abstract

Conjugated polymer photocatalysts for hydrogen production have the advantages of an adjustable structure, strong response in the visible light region, adjustable energy levels, and easy functionalization. Using an atom- and step-economic direct C–H arylation method, dibromocyanostilbene was polymerized with thiophene, dithiophene, terthiophene, and fused thienothiophene and dithienothiophene, respectively, to produce donor–acceptor (D-A)-type linear conjugated polymers containing different thiophene derivatives with different conjugation lengths. Among them, the D-A polymer photocatalyst constructed from dithienothiophene could significantly broaden the spectral response, with a hydrogen evolution rate up to 12.15 mmol h−1 g−1. The results showed that the increase in the number of fused rings on thiophene building blocks was beneficial to the photocatalytic hydrogen production of cyanostyrylphene-based linear polymers. For the unfused dithiophene and terthiophene, the increase in the number of thiophene rings enabled more rotation freedom between the thiophene rings and reduced the intrinsic charge mobility, resulting in lower hydrogen production performance accordingly. This study provides a suitable process for the design of electron donors for D-A polymer photocatalysts.

Functionalized Linear Conjugated Polymer/TiO2 Heterojunctions for Significantly Enhancing Photocatalytic H2 Evolution

“…Consistent with the PL and TPR results, the EIS experiments demonstrate that the order of the Nyquist circle radius is TSO 2 @TiO 2 < TS@TiO 2 < TFl@TiO 2 . Therefore, the smallest arc radius of the Nyquist plot for TSO 2 @TiO 2 means it has lower interfacial resistance and excellent charge mobility characters [ 60 , 61 , 62 ].…”

A Review of the Strategic Use of Sodium Alginate Polymer in the Immobilization of Microorganisms for Water Recycling

“…Therefore, significant attention has been paid to the development of hybrid materials—also known as coordination polymers [ 158 , 159 ]. Likewise, Ye et al [ 160 ] carried out studies on the use of conjugated polymer photocatalysts for hydrogen production. Overall, water treatment using Na-Alg is an efficient and environmentally friendly method.…”

A Comprehensive Review on the Boosted Effects of Anion Vacancy in the Heterogeneous Photocatalytic Degradation, Part II: Focus on Oxygen Vacancy

“…22−24 The performance of photocatalyst nanomaterials depends on light harvesting to produce photogenerated electron−hole pairs (charge carriers), their separation efficiency and transfer to the surface, and interfacial redox reactions on the active site of photocatalysts' surfaces. 25 To boost the activity of semiconductor photocatalysts, these drawbacks should be overcome by applying suitable strategies, like modification of their structure, control of their morphology, the plasmonic effect, engineering of their surface and interface, and engineering of their facets and defects. 26−29 Due to the critical roles of semiconductors' microstructural properties, including dimensions, morphologies, effective surface area, and pore dispersion, on the overall photocatalytic efficiency, a significant issue is rational semiconductor design and synthesis with well-designed structures.…”

“…The performance of photocatalyst nanomaterials depends on light harvesting to produce photogenerated electron–hole pairs (charge carriers), their separation efficiency and transfer to the surface, and interfacial redox reactions on the active site of photocatalysts’ surfaces . To boost the activity of semiconductor photocatalysts, these drawbacks should be overcome by applying suitable strategies, like modification of their structure, control of their morphology, the plasmonic effect, engineering of their surface and interface, and engineering of their facets and defects. − …”