Meng Li

The heterogeneous electro-Fenton (HEF) membrane has shown great potential for the treatment of refractory organic pollutants, but there are growing demands to improve its degradation efficiency and suitability for addressing practical organic pollutant issues. Here, a novel Co-CNT/Ti₃C₂T_X nanocomposite membrane was successfully prepared by vacuum filtration, followed by heat treatment. Different from the traditional batch reactor, a flow-through reactor with Co-CNT/Ti₃C₂T_X membrane was designed as an electrode to make the full use of the combined synergistic effect of adsorption and electro-Fenton (EF) process for the degradation of organic pollutants. The results found that the Co-CNT/Ti₃C₂T_X flow-through HEF system exhibited satisfactory degradation (99.0–83.2%) on tetracycline (TC) in a wide range of pH 2.0–7.0. In addition, the obtained Co-CNT/Ti₃C₂T_X membrane possesses self-cleaning performance in long-term continuous conditions. Co-CNT/Ti₃C₂T_X membrane can also be used to treat practical TC wastewater with complex components, tannery printing and dyeing wastewater, and wastewater with different water matrices, and their removal efficiency can reach more than 87.0%. Specially, the coupling effect could be beneficial to accelerate the degradation of pollutants in the EF process. The method provided in this work could be further expanded, making industrial usage of the HEF membrane a reality.

Gemini oleamidopropyl hydroxy sulfobetaine (GOHSB) was prepared and characterized. The CMC of GOHSB was 7.19 × 10^–5 and 8.74 × 10^–5 mol/L, and the surface tension of GOHSB and gel breaking liquid was 31.7 and 48.9 mN/m, respectively. The viscosity of 2 wt % at pH 4 was 71.5 mPa s at the shear rate of 170 s^–1 and the settling rate of proppant was 0.0047 mm/s. With the addition of 15000 mg/L of NaCl and CaCl₂, GOHSB viscosity (2 wt %) was 26.94 and 18.51 mPa s at the shear rate of 170 s^–1. τ was called relaxation time. At 1 wt %, the τ was 0.019 s, while at 2 wt %, τ reduced to 0.013 s. GOHSB solution with 1 wt % showed elastic characteristics.

Polymer film capacitors have been widely applied in many pulsed power fields owing to their fastest energy-released rates. The development of ferroelectric polyvinylidene fluoride (PVDF)-based composites has become one of the hot research directions in the field of high-energy storage capacitors. Recently, hierarchically-structured all-organic composites have been shown to possess excellent comprehensive energy storage performance and great potential for application. In this review, most research advances of hierarchically-structured all-organic composites for the energy storage application are systematically classified and summarized. The regulating strategies of hierarchically structured all-organic composites are highlighted from the perspective of preparation approaches, tailored material choices, layer thicknesses, and interfaces. Systematic comparisons of energy storage abilities are presented, including electric displacement, breakdown strength, energy storage density, and efficiency. Finally, we present the remaining problems of hierarchically structured all-organic composites and provide an outlook for future energy storage applications.

Green innovation investments have rapidly grown since 2000. Green innovation indexes play important roles and are typically constructed by screening and indexing. However, Nobel Laureate Markowitz emphasizes portfolio selection instead of security selection and accentuates that “A good portfolio is more than a long list of good stocks.” Moreover, the screening‐indexing strategies ignore that investors can take green innovation as an additional objective and thus gain additional utility. We consequently construct 3‐objective portfolio selection for green innovation in addition to variance and expected return. An efficient frontier of portfolio selection then extends to an efficient surface which is a panorama of the optimal variance, expected return, and expected green innovation. Investors thus fully envisage the trade‐offs and enjoy the freedom of choosing preferred portfolios on the surface. In contrast, the screening‐indexing strategies inflexibly leave investors with only one point (i.e., the green innovation index). As the originality, we prove in a theorem that there typically exists a curve on the efficient surface so all portfolios on the curve dominate the green innovation index. We test the dominance by component stocks of China Securities Index 300 and obtain affirmative results out of sample. The results still hold in robustness tests. At last, we classify green innovation into categories, further model the categories by general k‐objective portfolio selection, and still illustrate the dominance. Consequently, investors can consider and control each category.