Molecular Dipole‐Induced Photoredox Catalysis for Hydrogen Evolution over Self‐Assembled Naphthalimide Nanoribbons

Abstract

D‐π‐A type 4‐((9‐phenylcarbazol‐3‐yl)ethynyl)‐N‐dodecyl‐1,8‐naphthalimide (CZNI) with a large dipole moment of 8.49 D and A‐π‐A type bis[(4,4′‐1,8‐naphthalimide)‐N‐dodecyl]ethyne (NINI) with a negligible dipole moment of 0.28 D, were smartly designed and synthesized to demonstrate the evidence of a molecular dipole as the dominant mechanism for controlling charge separation of organic semiconductors. In aqueous solution, these two novel naphthalimides can self‐assemble to form nanoribbons (NRs) that present significantly different traces of exciton dissociation dynamics. Upon photoexcitation of NINI‐NRs, no charge‐separated excitons (CSEs) are formed due to the large exciton binding energy, accordingly there is no hydrogen evolution. On the contrary, in the photoexcited CZNI‐NRs, the initial bound Frenkel excitons are dissociated to long‐lived CSEs after undergoing ultrafast charge transfer within ca. 1.25 ps and charge separation within less than 5.0 ps. Finally, these free electrons were injected into Pt co‐catalysts for reducing protons to H2 at a rate of ca. 417 μmol h−1 g−1, correspondingly an apparent quantum efficiency of ca. 1.3 % can be achieved at 400 nm.

Simultaneous photocatalytic H2generation and organic synthesis over crystalline–amorphous Pd nanocube decorated Cs3Bi2Br9

“…Photocatalytic H 2 generation is considered a promising strategy for the sustainable production of energy. [1][2][3][4][5] Recently, metal halide perovskites (MHPs) have emerged as efficient H 2 evolution photocatalysts. [6][7][8] However, most of the H 2 evolution reaction (HER) experiments are performed in saturated aqueous hydrohalic acid HX (X = Br and I) solutions using the dynamic dissolution-reprecipitation equilibrium to keep the MHP stable.…”

Photocatalytic Anaerobic Dehydrogenation of Alcohols over Metal Halide Perovskites: A New Acid-Free Scheme for H2 Production

“…Clean H 2 is widely identified as an ideal energy carrier for realizing a carbon-neutral society. − However, over 95% of the world’s H 2 is currently produced from steam methane re-forming, which consumes huge amounts of fossil fuels and releases massive amounts of CO 2 (40 billion metric tons/year). − Solar-driven photocatalytic H 2 evolution over semiconductors has long been investigated as a sustainable alternative exploiting the abundance and inexhaustibility of solar energy. − Recently, metal halide perovskites (MHPs) have emerged as promising new-generation photoabsorbers because of their outstanding optoelectronic characteristics, such as a broad light absorption range, − high absorption coefficient, , and long charge diffusion length and lifetime. − These attractive features enable a broad range of photovoltaic and optoelectronic applications of these materials toward solar energy conversion. , …”

Supramolecular coassembly: monomer pair design, morphology regulation and functional application

“…43 Considering that the charge transfer features within SCAs facilitate charge transport pathways, lots of effort has been paid to apply these assemblies as organic photocatalysts for photocatalytic H 2 production and CO 2 reduction. 92,93 Recently, Zhu's group developed a series of promising supramolecular photocatalytic materials derived from porphyrin, perylene diimide and perylene derivatives. [94][95][96] For instance, they constructed a full-spectrum (300-850 nm) responsive donor-acceptor SCA photocatalyst tetraphenylporphinesulfonate/fullerene, showing a highly efficient H 2 production performance with an average rate of 34.57 mmol g À1 h À1 .…”