A 3D/0D cobalt-embedded nitrogen-doped porous carbon/supramolecular porphyrin magnetic-separation photocatalyst with highly efficient pollutant degradation and water oxidation performance

A 3D/0D cobalt-embedded nitrogen-doped porous carbon nanocubes(Co-N-C)/supramolecular tetra(4-carboxylphenyl)porphyrin nanocrystals(SA-TCPP)photocatalyst was successfully self-assembled viaπ–πinteraction,hydrogen bonding,and chemical bonding.Co-N-C/SA-TCPP heterostructure exhibited satisfactory visible photocatalytic oxidation performance on pollutant degradation and water evolution.The degradation rates of Co-N-C/ST(30%)composite towards 2,4-dichlorophenol,ofloxacin,and ethylene were10.9,7.2,and 2.1 times faster than SA-TCPP,respectively.The oxygen evolution efficiency was 1.9 times higher than SA-TCPP.The remarkably improved oxidation activities of Co-N-C/SA-TCPP were mainly ascribed to the following reasons:(1)Co-N-C could enhance the light absorption ability of SA-TCPP to produce more photoinduced carriers.(2)The well-developed porosity of Co-N-C could optimize the dispersibility of SA-TCPP to provide more reactive sites and charge separation channels.(3)Theπ–πinteraction between SA-TCPP and Co-N-C was beneficial to interlayer charge mobility,while the embedded cobalt nanoparticles(Co NPs)and N-doped carbon matrix could serve as electron traps to accelerate interfacial electron transfer.Additionally,the ferromagnetic Co NPs endowed Co-N-C/SA-TCPP with magnetic-separation function to promote recyclability in practical application.

Mssbauer Study of Coal Desulfurization by Microwave Irradiation Combined With Manetic-Separation and Chemical Acid-Leaching

^(57)Fe Mssbauer spectroscopy was used to study the mechanism and regularity of coal desulfurization by microwave irradiation combined with magnetic-separation and with chemical acid-leaching. The results of phase analyses show that the decomposing reaction of pyrite intrinsic in coal, caused by the selective dielectric heating of microwave electromagnetic energy, FeS_2→Fe_(1-x)S→FeS, consecutively progresses towards the right-hand side with increased irradiation time. The whole process of microwave desulfurization of raw coal consists of the initiation, the promotion, and the saturation stages. The optimum desulfurization efficiency for microwave irradiation combined with magnetic-separation treatment and with chemical acid-leaching treatment can be attained by appropriately controlling the irradiation time to enable the corresponding microwave treatment to lie in the promotion stage and the saturation stage, respectively.