Li Yuanling, Liu Lina, Yu Han, Zhao Yinglun, Dai Jing, Zhong Yaping, Pan Zhicheng, Yu Hongbing
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Engineering Centre for Cleaner Technology of Iron-steel Industry, College of Environmental Science and Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Engineering Centre for Cleaner Technology of Iron-steel Industry, College of Environmental Science and Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, China.
Sci Total Environ. 2022 Mar 10;811:151384. doi: 10.1016/j.scitotenv.2021.151384. Epub 2021 Nov 4.
With the aim of relieving the serious environmental and climate issues arising from excessive emission of anthropogenic CO, extensive solid absorbents have been developed for CO capture. Among them, porous boron nitride (BN) is considered an ideal candidate due to its high specific surface area, abundant structural defects, low density, and outstanding chemical inertness. Herein, BN absorbents were synthesized from pyrolysis of melamine-boric acid precursors, and the effect of pyrolysis temperature (900, 1000, 1050 and 1100 °C) on the properties and performances was investigated. Various characterizations were performed to evaluate the physicochemical properties and CO uptake capacities of BN absorbents. The result demonstrated that a carbon-doped BN structure was achieved instead of a pure BN material, and the carbonization degree was enhanced with the increase of pyrolysis temperatures. BN absorbent pyrolyzed at 1100 °C exhibited the highest CO adsorption capacity of 3.71 mmol/g (273 K). The reason should be that the doping of carbon in the framework of BN contributed to the formation of abundant micropores, which enhanced the physical adsorption by offering more adsorption sites. At the same time, more negative charges on BN were induced by structural defects, which favored the chemical adsorption of CO by invoking charge-induced chemisorption interaction. This study clarified the role of pore structure and electronic structure defects in CO adsorption capacity of carbon-doped BN, which would open up more spacious avenues for the development of promising BN-based absorbents, or even catalysts.
为了缓解因人为二氧化碳过度排放而产生的严重环境和气候问题，人们开发了大量的固体吸附剂用于二氧化碳捕集。其中，多孔氮化硼（BN）因其高比表面积、丰富的结构缺陷、低密度和出色的化学惰性而被认为是理想的候选材料。在此，通过三聚氰胺-硼酸前驱体的热解合成了BN吸附剂，并研究了热解温度（900、1000、1050和1100℃）对其性能和表现的影响。进行了各种表征以评估BN吸附剂的物理化学性质和二氧化碳吸收能力。结果表明，获得的是碳掺杂的BN结构而非纯BN材料，且碳化程度随热解温度的升高而增强。在1100℃热解的BN吸附剂表现出最高的二氧化碳吸附容量，为3.71 mmol/g（273 K）。原因应该是BN骨架中碳的掺杂有助于形成丰富的微孔，通过提供更多吸附位点增强了物理吸附。同时，结构缺陷在BN上诱导了更多负电荷，通过引发电荷诱导化学吸附相互作用有利于二氧化碳的化学吸附。本研究阐明了孔结构和电子结构缺陷在碳掺杂BN的二氧化碳吸附容量中的作用，这将为开发有前景的BN基吸附剂甚至催化剂开辟更广阔的道路。
