研究目的
To design and synthesize donor-acceptor conjugated microporous polymers with tunable band gaps for enhanced photocatalytic hydrogen evolution from water under visible light irradiation.
研究成果
The donor-acceptor CMPs exhibit tunable band gaps and emission colors, with F0.5CMP showing the highest photocatalytic hydrogen evolution due to optimal band gap (2.3 eV). The approach enables efficient visible-light-driven water splitting without noble metal co-catalysts, offering potential for applications in light-emitting devices and photovoltaics.
研究不足
The polymers are amorphous and non-porous to N2, with limited porosity for CO2. Residual palladium from synthesis may influence results, but its role is minimized. Comparison with other studies is difficult due to variations in experimental setups. The lowest band gap polymer (F2.0CMP) shows reduced activity due to non-radiative recombination.
1:Experimental Design and Method Selection:
The study involves the synthesis of a series of donor-acceptor conjugated microporous polymers (CMPs) using Pd-catalyzed Suzuki-Miyura cross-coupling reactions. The polymers are characterized using FT-IR, solid-state 13C-CP-MAS NMR, PXRD, FESEM, TGA, and gas adsorption measurements. Photophysical properties are analyzed using UV-Vis absorption, photoluminescence spectroscopy, and fluorescence lifetime decay. Photocatalytic hydrogen evolution experiments are conducted under broad-spectrum and visible light irradiation using a Xe lamp.
2:Sample Selection and Data Sources:
Polymers F0.0CMP, F0.1CMP, F0.5CMP, and F2.0CMP are synthesized with varying equivalents of 9-fluorenone acceptor. Samples are purified via Soxhlet extraction.
3:0CMP, F1CMP, F5CMP, and F0CMP are synthesized with varying equivalents of 9-fluorenone acceptor. Samples are purified via Soxhlet extraction.
List of Experimental Equipment and Materials:
3. List of Experimental Equipment and Materials: Equipment includes a Schlenk tube for synthesis, Soxhlet extractor, FT-IR spectrometer, NMR spectrometer, PXRD, FESEM, TGA, gas adsorption analyzer, UV-Vis spectrophotometer, fluorescence spectrometer, time-correlated single photon counting system, photocatalytic reactor with Xe lamp, and gas chromatography. Materials include tetrakis(4-bromophenyl)ethene, 2,7-dibromo-9H-fluoren-9-one, 1,4-benzenediboronic acid, Pd(PPh3)4, solvents (DMF, THF, methanol, DCM), and sacrificial agents (Na2S, Na2SO4).
4:4).
Experimental Procedures and Operational Workflow:
4. Experimental Procedures and Operational Workflow: Synthesis involves cross-coupling reactions under N2 atmosphere, purification, activation, and characterization. Photocatalytic tests involve dispersing 5 mg polymer in water/MeOH with sacrificial agents, degassing, irradiation, and H2 quantification by GC.
5:Data Analysis Methods:
Band gaps are calculated using Kubelka-Munk plots. Hydrogen evolution rates are determined from GC data. Statistical analysis includes correlation of H2 rates with band gaps.
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