“Light-assisted evaporation induced self-assembly”: an efficient approach toward ordered carbon materials

Abstract

The synthesis of ordered porous carbons by a green, simple and rapid approach based on light exposure of a solution of carbon precursors and a soft-template in the presence or not of a photosensitizer is demonstrated herein along with their formation mechanism. The influence of the benzophenone amount on the formation of phenolic resin and the carbon structure, morphology and textural properties was systematically studied. The polymerization, self-assembly and carbonization are promoted in the same step by light. The benzophenone accelerates several times the reaction rate modifying mainly the phenolic-resin structure (higher degree of cross-linking and carbonization) via radical formation, as highlighted by Raman spectroscopy. In addition, the increase of benzophenone amount gradually induces the modification of carbon morphology from a worm-like disordered structure to a highly organized hexagonal one while the surface area and pore volume remain unchanged. The 13 C and 1 H solid state and relaxation NMR analysis pointed out that this behavior is triggered by the different micellar structuration of the template in the presence of benzophenone, the phenolic-resin composition involving only carbon precursor derived compounds and not benzophenone. † Electronic supplementary information (ESI) available: Experimental synthesis procedure, DFT pore size distribution; unit cell evolution for phenolic-resins and carbons; TEM pictures of carbons prepared under specic conditions; Raman spectra of phenolic resins. See

Direct synthesis of graphitic mesoporous carbon from green phenolic resins exposed to subsequent UV and IR laser irradiations

“…3c). For all materials, a peak located around 0.05 nm −1 (q) is noticed corresponding to (100) reflections of an ordered 2-D hexagonal structure212324. When the irradiation time increases from 5 min (CGY-L5) to 60 min (CGY-L60), the peaks become more intense and narrow indicating improvement of phenolic resin and carbon organization, in good agreement with the TEM pictures (Fig.…”

“…1a. The self-assembly of phloroglucinol-glyoxylic acid phenolic resin via H-bonding with the PPO and PEO blocks of Pluronic template cannot be excluded either23.…”

“…Such isotherm is characterized by an increase of the adsorbed nitrogen quantity in the low relative pressure range (P/P 0  < 0.1) due to the micropores formed by the decomposition of phenolic-resin. The hysteresis is related to the capillary condensation in the mesopores formed by the thermal decomposition of Pluronic template23. The hysteresis loop for CGY-L5 (5 min irradiated) and CGY-L15 (15 min irradiated) is placed between 0.4 and 0.8 P/P 0 and becomes much narrow in comparison with CGY-L30 (30 min irradiated) and CGY-L60 (60 min irradiated), 0.4–0.7 and 0.4–0.5 P/P 0 , respectively.…”

“…In order to decrease the time of MC synthesis, several improvements were proposed by using high acidic conditions18 and/or high pressure (autoclaving)22 treatments. We have proposed recently a time efficient procedure to obtain mesoporous carbon via photopolymerization, i.e., light-assisted evaporation induced self-assembly (LA-EISA)2324. We demonstrated that the classical long thermopolymerization at high temperatures (12 hours at 80 °C) may be replaced by 60 minutes of irradiation with an UV lamp source at room temperature.…”

Mesoporous carbon supported ultrasmall palladium particles as highly active catalyst for Suzuki‐Miyaura reaction

“…Catalyst C1 was prepared by a two‐step bottom‐up synthesis approach (Scheme ) involving first the synthesis of the carbon porous support and then the formation of Pd nanoparticles in the carbon network. The carbon was obtained by self‐assembly of phenolic resin precursors (phloroglucinol‐glyoxal) with a pore creating agent (Pluronic F‐127) followed by thermal annealing which led to the formation of a porous carbon . In a second step, the impregnation of this carbon with a Pd‐based salt solution followed by thermal reduction (Scheme ) led to the formation of Pd/Carbon catalyst C1 possessing Pd nanoparticles of a narrowly distributed size and a homogeneous repartition on the carbon surface, as revealed by STEM images (Figure a, b).…”