Piezoelectric nanomaterials have been utilized to realize effective charge separation for degrading organic pollutants in water under the action of mechanical vibrations. However, in particulate form, the nanostructured piezoelectric catalysts can flow into the aqueous pollutant and limit its recyclability and reuse. Here, we report a new method of using a barium titanate (BaTiO 3 , BTO)−polydimethylsiloxane composite porous foam catalyst to address the challenge of secondary pollution and reusable limits. Piezo-catalytic dye degradation activity of the porous foam can degrade a Rhodamine B (RhB) dye solution by ∼94%, and the composite material exhibits excellent stability after repeated decomposition of 12 cycles. It is suggested that under ultrasonic vibrations, the piezoelectric BTO materials create separated electron−hole pairs that react with hydroxyl ions and oxygen molecules to generate superoxide ( • O 2 − ) and hydroxyl ( • OH) radicals for organic dye degradation. The degradation efficiency of RhB is associated with the piezoelectric constant, the specific surface area, and the shape of the material.

Thermal energy harvesting from the ambient environment through thermoelectric nanogenerators (TEGs) is an ideal way to realize self‐powered operation of electronics, and even relieve the energy crisis and environmental degradation. As one of the most significant energy‐related technologies, TEGs have exhibited excellent thermoelectric performance and played an increasingly important role in harvesting and converting heat into electric energy, gradually becoming one of the hot research fields. Here, the development of TEGs including materials optimization, structural designs, and potential applications, even the opportunities, challenges, and the future development direction, is analyzed and summarized. Materials optimization and structural designs of flexibility for potential applications in wearable electronics are systematically discussed. With the development of flexible and wearable electronic equipment, flexible TEGs show increasingly great application prospects in artificial intelligence, self‐powered sensing systems, and other fields in the future.

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In this study, a Zn-Pr antibacterial white carbon black was synthesised via a sol-gel method. The Box-Behnken design of response surface methodology was applied to optimise the antibacterial product. Statistical analysis revealed that the particle size of the Zn-Pr antibacterial white carbon black was significantly affected by reaction time, reaction temperature and Zn ion concentration. The optimum reaction time, temperature and Zn ion concentration were 1.03 h, 88.64 °C and 0.05 mol L −1 , respectively. The product was characterised through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive spectroscopy analysis. The antibacterial properties of the Zn-Pr antibacterial white carbon black on Escherichia coli. were also investigated. The bacteriostatic rate of Zn-Pr antibacterial white carbon black was 95.24%.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS) were listed under Stockholm convention on persistent organic pollutants owing to their poor biodegradability and toxic effects in the environment, so various strategies were reported for synthesizing non-bioaccumulable alternatives to them. Herein, we described our recent strategies for synthesis of non-bioaccumulable fluorinated surfactants by introducing branched perfluorinated chain using perfluoro-2-methyl-2-pentene as starting material. Novel branched fluorinated cationic, gemini and amphoteric surfactants were designed and prepared through a four-step route. They all have low solubility in water and exhibit poor ability to reduce the surface tension of water. A series of branched fluorinated nonionic surfactants with different length of hydrophilic chains were synthesized via a three-step route. The solubility becomes larger with the increase of the value of polymerization degree of polyethylene glycol. But, the surface tension measurement results show that their ability and efficiency to reduce the surface tension of water change little when the value of polymerization degree of polyethylene glycol is equal to or greater than 4. All the values of surface activities of the novel 20～22 surfactants (take the compound 20 for example, about 21.4 mN/m at the cmc 4.4×10-5 mol/L) are lower than that of sodium perfluorooctanoate (about 24.7 mN/m at the cmc 3.1×10-2 mol/L). Methyl-benzenesulfonic acid (compound 23) was synthesized through a two-step route. Both the steps are easy work-up, mild reaction conditions, low cost and high yields. The surfactant exhibits excellent ability to reduce the surface tension of water to 20.8 mN/m. Besides, it has good salt-resistance. The acute toxicity of 20 was investigated and the result shows that the acute oral toxicity LD 50 Value of the compound 20 was 3160 mg/kg which is higher than that of ammonium perfluorooctanoate (C 7 F 15 COONH 4 , 470～540 mg/kg). So preparing branched fluorinated surfactants using hexafluoropropylene (HFPD) is a simple, economical and environmentally friendly method for synthesis of alternatives to PFOA and PFOS.