With rapid industrial development, the massive generation of nitrogenous wastewater poses a serious threat to both human beings and the ecosystem. Bio-based adsorbents are considered promising adsorption materials for many applications. However, their complex preparation procedures, large energy consumption, and difficulty of microstructure control hinder their practical applications. In this study, a new corncob-derived porous adsorbent (CPA) with excellent urea adsorption capacity in wastewater was prepared by the one-step hydrothermal process. The effects of the hydrothermal process conditions on the urea adsorption capacity of the CPA were evaluated and optimized using the response surface methodology, and a kinetic analysis of the CPA was also carried out. Our findings showed that the adsorption process of urea by the adsorbent followed the Langmuir isotherm and pseudo-second-order kinetic models. The high adsorption capacity for urea was attributed to the abundant porous structure and the hydrogen bonds formed between the adsorbent and the amine group in urea, which made it more conducive to the adsorption of urea. Therefore, we believe that CPA could be a promising adsorbent for urea removal in wastewater.

Heat dissipation has become an essential factor affecting the performance and operating life of electronic devices as the development of modern electronic devices continues to miniaturize and integrate to increase power density. The development of new thermal interface materials has been the key solution to heat dissipation. Herein, a high thermal conductive graphene‐based hydrogel (G/PVP‐PVA) with an interpenetrating network is successfully constructed by physical cross‐linking combined with the freeze–thaw process. The effect of the preparation parameters on its all‐around performance is evaluated in detail. When the graphene dosage is 0.33%, the maximal tensile stress of the hydrogel is 322.4 kPa, the self‐recovery is 95.4%, and the thermal conductivity is as high as 1.486 W m−1 K−1. The cooling simulation experiment shows that the hydrogel can adhere closely to the wall to reduce the air thermal resistance effectively, and the cooling rate is as high as 5.04 °C min−1. The simulation experiment of the human body cooling shows that its cooling rate is 1.10 °C min−1, while that for a commercial hydrogel is 0.27 °C min−1. The G/PVP‐PVA can give a practically potential solution for the thermal management of flexible electronic products and provides a new material for an efficient medical cooling application.

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