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Both porous and scale-like wall zirconia (ZrO2) hollow microspheres were successfully prepared through a facile and mild microwave solvothermal method using the rape pollen as biotemplates. The formation mechanisms were discussed for both ZrO2 hollow microspheres fabricated using pollen biotemplate with different pollen treatments. The porous ZrO2 hollow microspheres had a specific surface area of 40.92 m2·g–1, significantly higher than scale-like wall ZrO2 hollow microspheres (24.79 m2·g–1) and ZrO2 particles (27.99 m2·g–1). The adsorption test results showed that porous ZrO2 hollow microspheres had a higher adsorption capability (96.98 g·mg–1) than scale-like wall ZrO2 hollow microspheres (38.55 g·mg–1) and ZrO2 particles (32.03 g·mg–1) for Congo red. The adsorption followed pseudo-second-order kinetics, and the adsorption process was homogeneous adsorption of monolayer.

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Negative dielectric constant has long been pursued for a possible revolution in electronics and photonics. It is usually found in systems containing free electrons under high frequency oscillating field, but not involving static charges or insulating materials. Here, we report the observation of the phenomenon in an insulating polymer containing static electricity, which lasts for several weeks, where negative capacitance persists from <1 Hz up to MHz frequency, also presenting an unusual spiral curve in impedance spectrum, producing inductors without bulky magnetic coils.

Fuel cells have attracted more attentions due to many advantages they can provide, including high energy efficiency and low environmental burden. To form a stable, low cost and efficient catalyst, we presented here the state of the art of electrocatalyst fabrication approaches, involving carbon nanotubes and their multifunctional nanocomposites incorporated with noble metals, such as Pt, Pd, Au, their binary and ternary systems. Both fuel oxidation reactions and oxygen reduction reactions were emphasized with comprehensive examples and future prospects.