Organic Photovoltaic Catalyst with σ‐π Anchor for High‐Performance Solar Hydrogen Evolution

Abstract

Efficient in situ deposition of metallic cocatalyst, like zero‐valent platinum (Pt), on organic photovoltaic catalysts (OPCs) is the prerequisite for their high catalytic activities. Here we develop the OPC (Y6CO), by introducing carbonyl in the core, which is available to σ‐π coordinate with transition metals, due to the high‐energy empty π* orbital of carbonyl. Y6CO exhibits a stronger capability to anchor Pt species and reduce them to metallic state, resulting in more Pt0 deposition, relative to the control OPC without the central σ‐π anchor. Single‐component and heterojunction nanoparticles (NPs) employing Y6CO show enhanced average hydrogen evolution rates of 230.98 and 323.22 mmol h−1 g[OPC]−1, respectively, under AM 1.5G, 100 mW cm−2 for 10 h, and heterojunction NPs yield the external quantum efficiencies of ca. 10 % in 500–800 nm. This work demonstrates that σ‐π anchoring is one efficient strategy for integrating metallic cocatalyst and OPC for high‐performance photocatalysis.

Hydroxylated organic semiconductors for efficient photovoltaics and photocatalytic hydrogen evolution

“…A high EQE of the PM6:BTP-2OH NPs was obtained with values of 8.58% at 600 nm, 9.08% at 700 nm, and 9.17% at 800 nm among the best results in the long-wavelength region (>500 nm) for the OSC BHJ-based photocatalysts (see Table S1, ESI†). 19–22,45 In comparison, the PM6:BTP-FOH NPs also exhibit impressive EQEs of 6.84% at 600 nm, 7.98% at 700 nm, and 8.35% at 800 nm, and the PM6:BTP-4F NPs show moderate EQEs of 3.69% at 600 nm, 6.72% at 700 nm, and 7.12% at 800 nm.…”

Phenoxazine-based small molecule heterojunction nanoparticles for photocatalytic hydrogen production

“…S6b, ESI†). The overall rates of H 2 production for designed molecular heterojunction NPs were among the most efficient small organic molecule based photocatalysts, 5,6,18,19 and even higher than those observed for many of the polymer-based heterojunction NPs, 16,17,26,27 and inorganic photocatalysts. 28 Having molecular donor and molecular acceptor that both can form crystalline structures, results in enhanced mixing, structure ordering and thus charge delocalization.…”

“…4,7,16,17 Recently, several works used small molecule NPs that showed impressive external quantum efficiencies even in the absence of polymeric donors. 5,6,[18][19][20] Small molecules offer highly tunable molecular structure, band gap and energy levels. And in contrast to most polymers, small molecules demonstrated the ability to form favorable morphology with highly crystalline networks that may offer efficient generation of free carriers, and thus suppressed recombination rates.…”

“…The field of photocatalysis has largely expanded in solar fuel research in the last few years, and now organic photocatalysts are of growing interest due to their biocompatibility and ability to work with various (co-)catalysts to generate a wide range of valuable products from water, CO 2 and sunlight, e.g. H 2 , 1–8 H 2 O 2 , 9–11 formate, 9 poly-3-hydroxybutyrate, 12 acetate, 13 2-oxobutyrate, 14 etc.…”

Mechanistic Insights into the Photocatalytic Hydrogen Production of Y5 and Y6 Nanoparticles

“…Dolan et al tested Y6 NPs for photocatalytic hydrogen production and highlighted the impact of surfactants for their application . In addition, molecular engineering of small-molecule photocatalysts showed significantly improved photocatalytic hydrogen production, suggesting satisfactory charge separation in small-molecule NPs. − However, understanding the photophysical properties, particularly excitonic and charge separation processes in small-molecule NPs, is necessary for new molecular photocatalyst design. Excitonic effects and important excitonic processes set limitations to the overall photocatalytic quantum yield.…”