Salt-template hydrothermal carbonization for Pd NP-loaded porous carbonaceous material

Abstract

Inorganic salt is a promising stabilizer in the hydrothermal synthesis of porous carbon materials. A three-dimensional palladium-loaded (Pd-loaded) lignin carbonaceous material with a porous structure was developed via hydrothermal carbonization, with lignin as not only a carbon source but also a reducing and stabilizing agent for palladium nanoparticles (Pd NPs) and then with LiCl as the hard template and porogen. The porogen-induced Pd-loaded carbonaceous material displayed an orderly pore structure with more porosity than the porogen-free Pd-loaded carbonaceous material. Subsequently, the porogen-induced Pd-loaded carbonaceous materials were transferred to an aqueous phase filter and mixed with reactants in a syringe as catalysts. The catalyst exhibited excellent catalytic performances in the reduction reaction of 4-nitrophenol to 4-aminophenol by NaBH4, with a rate constant of 0.11 min-1, which was higher than that of the porogen-free Pd-loaded carbonaceous material. In this study, LiCl was employed as the hard template and porogen to construct the porous carbonaceous structure and improve the porosity by stabilizing the pore structure and minimizing collapse, which provided a new way to synthesize lignin porous carbonaceous material.

Salt-Induced Doping and Templating of Laser-Induced Graphene Supercapacitors

“…29 From this data, along with the TEM images, which demonstrate wrapping of the LIG around embedded salt particles, we believe that the salt particles act as a template or porogen in the PFA composite, enabling the formation of a higher surface area carbon material. Salt particles such as LiCl have been utilized in this manner as a hard template during the hydrothermal carbonization of lignin, to result in a higher surface area carbon material, 43 and salts such as ZnCl 2 and Na 2 CO 3 have been employed in the chemical activation of carbons at high temperature to boost carbon surface areas. 41 XPS analysis was then performed on the LIG powders to further investigate their chemical structures.…”

“…Likewise, salt particles have been previously utilized as templating and pore-forming agents in order to increase the porosity and surface area of carbon materials. 43 Herein, we demonstrate that the addition of micron-sized particles of sodium salts such as sodium chloride (NaCl) and sodium sulfate (Na 2 SO 4 ) into PFA dramatically changes the resulting LIG material after laser irradiation. The addition of salt particles increases the BET surface area of the LIG formed by over an order of magnitude and also results in the formation of either Cl-or S-doped LIG depending on the salt used, resulting in LIG electrodes that exhibit a capacitance ∼2500× that of pristine PFA.…”

“…As the local temperatures during laser scribing can reach thousands of degrees, the presence of salt in the PFA material may result in a similar effect during laser irradiation. Likewise, salt particles have been previously utilized as templating and pore-forming agents in order to increase the porosity and surface area of carbon materials …”

Aramid Nanofibers Aerogel‐filled Wood‐based Carbon Material for Flexible Solid Supercapacitors

“…The slender wood cells were mainly composed oriented cellulose elementary fibrils and the matrix of hemicellulose and lignin. And the meddle lamella are mainly composed of lignin [19] . Our preliminary research has shown that the delignified wood composed of well‐aligned microchannels (mainly composed of aligned cellulose microfibrils) and abundant intertubular cavities (space of the middle lamella lignin) possess good mechanical flexibility [20] .…”

“…And the meddle lamella are mainly composed of lignin. [19] Our preliminary research has shown that the delignified wood composed of well-aligned microchannels (mainly composed of aligned cellulose microfibrils) and abundant intertubular cavities (space of the middle lamella lignin) possess good mechanical flexibility. [20] After carbonization, the delignified wood-based carbon materials also exhibit good mechanical flexibility.…”