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Waste plastics collected from local food courts were catalytically pyrolyzed and decomposed to produce carbon nanomaterials (CNMs) as well as hydrogen-rich gases as byproducts in this work. A series of bimetallic catalysts: Co–Fe, Co–Ni, and Fe–Ni with MgO as the catalyst support were synthesized and compared for the process. Products including high value-added carbon nanomaterials and gases were characterized to evaluate the activity of each bimetallic catalyst. In addition, products from four types of plastic: LDPE-plastic bags for bagging, PP-plastic bottles for drinking, PS-plastic lids, and PET-mineral water bottles were further comprehensively compared in terms of yield, purity of carbon, and adsorption capacity. Results show that Fe–Ni–Mg prepared by the pH-increase precipitation method exhibited the best performance for plastic conversion, contributing to the maximum CNM yield of 30.25 wt % and hydrogen yield of 31.52 mmol/gplastic. However, the Co–Ni/MgO synthesized by impregnation gave the least activity. Regarding the different plastic types, plastic waste from LDPE bags produced hydrogen with a relatively high yield of 35.27 mmol/gplastic, while PS lid plastic resulted in a relatively high CNM yield of 38.26 wt %. It is also found that the PET bottle was not suitable for CNM production accompanied by a high content of CO2 in product gases. The CNMs were further applied as adsorbents for wastewater treatment. The plastic-derived CNMs show strong (∼180 mg/gCNM) adsorption capacity of metal cations such as Fe, Ag, and Ni.

Pine pollen offers an all-natural multicavity structure with dual hollow air sacs, providing ample cargo capacity available for compound loading. However, the pollen exhibits reduced permeability because of the presence of a thin natural water-proofing layer of lipidic compounds. Herein, we explore the potential for compound loading within pine pollen and the potential for developing all-natural formulations for targeted delivery to the intestinal tract. Removal of the surface-adhered lipidic compounds is shown to improve surface wetting, expose nanochannel structures in the outer pollen shell and enhance water uptake throughout the whole pollen structure. Optimization of loading parameters enabled effective compound loading within the outer pollen shell sexine structure, with bovine serum albumin (BSA) serving as a representative protein. All-natural oral delivery formulations for targeted intestinal delivery are developed based on tableting of BSA-loaded defatted pine pollen, with the incorporation of xanthan gum as a natural binder, or ionotropically cross-linked sodium alginate as an enteric coating. Looking forward, the large cargo capacity, ease of compound loading, competitive cost, abundant availability, and extensive historical usage as food and medicine make pine pollen an attractive microencapsulant for a wide range of potential applications.