A Novel Magnetic Carbon Based Catalyst Synthesized from Reed Straw and Electric Furnace Dust for Biodiesel Production

In the era of serious greenhouse gas emission and energy shortage,it is necessary to use solid waste to prepare new renewable materials.In this work,the potential application of reed straw and electric furnace dust was explored.Firstly,magnetic carbon carrier(EFD&C)was prepared by high temperature calcination,and then magnetic carbon catalyst(SM@EFD&C)was prepared by activation of sodium methoxide.The catalyst was used to prepare biodiesel by transesterification reaction to test its activity and stability.Reed biochar,EFD&C and SM@EFD&C were detected by Diffraction of X-rays(XRD),Fourier transform infrared(FT-IR),Inductively coupled plasma(ICP),Scanning electron microscope(SEM),Transmission electron microscope(TEM),Brunauer-Emmett-Teller(BET),Vibrating sample magnetometer(VSM),Temperature programmed desorption of CO_(2)(CO_(2)-TPD)and Thermogravimetric analysis(TG-DTG).The results showed that SM@EFD&C catalyst had some characteristics including porous structure,easy adsorption and better magnetism.Under the reaction conditions of 65℃for 2 h with 6 wt%catalyst and methanol/oil molar ratio of 15:1,the biodiesel yields from reed biochar and EFD&C were only 4.88 wt%and 0.03 wt%,respectively,while the yield from SM@EFD&C catalyst reached 93.14 wt%(89.84 wt%after 7 cycles)under the same conditions,which proved that it had good catalytic activity and stability when used in biodiesel production.This study is of great significance of carbon dioxide emission reduction and environmental protection.

Thermal photonics with broken symmetries

Nanophotonic engineering provides an effective platform to manipulate thermal emission on-demand,enabling unprecedented heat management superior to conventional bulk materials.Amongst a plethora of nanophotonic structures,symmetries play an important role in controlling radiative heat transfer in both near-field and far-field.In physics,broken symmetries generally increase the degree of freedom in a system,enriching the understanding of physical mechanisms and bringing many exciting opportunities for novel applications.In this review,we discussed the underlying physics and functionalities of nanophotonic structures with broken geometrical symmetries,engineered mode symmetries,and broken reciprocity for the control of thermal emission.We overview a variety of physical phenomena and interesting applications,and provide the outlook for future development.