Two-dimensional porous carbon derived from pollen with enlarged interlayer distance enhanced electrocatalytic oxidation of n-valeraldehyde to octane

Electrocatalytic n-valeraldehyde oxidation reaction was an inexpensive and eco-friendly method to control n-valeraldehyde contamination and produce high value-added octane.However,low-cost and readily available electrocatalysts with high current efficiency were urgently needed.Herein,two-dimensional porous carbon derived from pollen with enlarged interlayer distance was built by alkali activation method,applying in electrocatalytic n-valeraldehyde oxidation reaction.The enlarged interlayer distance was verified by X-ray diffraction(XRD)and high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM).Electrocatalytic experiments consequences showed activated biomass derived carbon possessed a higher electrocatalytic activity and octane selectivity than unactivated catalyst.Systematic tests and in situ infrared experiments demonstrated that enlarged interlayer distance was positively correlated with specific surface area of catalysts,large specific surface area provided abundant absorption sites,facilitated the adsorption for n-valeraldehyde,and further promoted the transformation of n-valeraldehyde to octane.This work also provides a new avenue for creating high-performance electrocatalysts in terms of lattice engineering.

An angle-insensitive electromagnetic absorber enabling a wideband absorption

Electromagnetic(EM)wave absorbers with wideband absorption capability are proposed as a strategy to mitigate environmental pollution by EM waves.However,designing an EM absorber with its performance capacity independent of the EM wave incident angle remains elusive to date.Resolving this challenge requires development of EM absorbers whose EM absorption performance is insensitive to the EM wave incident angle.Herein,we synthesized EM absorbers with a variety of structures with different symme-tries(including micro-/nanospheres,nanoflakes and nanotubes)to study the effect of the EM absorbers’structure and the EM wave incident angle on the EM absorption performance.Our analysis reveals that non-magnetic EM absorbers with spatially symmetric nanostructures exhibit excellent EM wave incident angle-insensitivity.Finally,we demonstrate that a class of non-magnetic EM absorbers made from bam-boo derived-carbon nanospheres exhibit EM incident angle-insensitivity and wideband EM absorption performance with an effective absorption band up to 3.5 GHz when the thickness is 1.4 mm,a signif-icant improvement from prior studies which used thicknesses as high as 3-4 mm for comparable EM absorption performance.