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The BP@PVP Ionogel sensor with sensitive performance, robust interfacial adhesion and thermal tolerance should be provided a potential application in health-care monitoring or human-computer user interfaces.

An innovative ion conducting ice gel served as a solid-state electrolyte in a flexible supercapacitor with improved extreme low-temperature tolerance.

Single atom catalysts (SACs) exhibit desirable catalytic properties in key renewable energy reactions and devices. However, rational design of SACs and boosting their performances for oxygen electrocatalysis and rechargeable Zn–air batteries (ZABs) are still crucial yet challenging. Herein, single Co atoms anchored in ultrathin N, P-codoped porous carbon nanosheets (CoSA/NPC) were prepared by an in situ confinement pyrolysis strategy. The ultrathin nanosheet structure provides an ideal platform for high exposure of the generated Co active sites and extremely shortens the electron transport pathways. Both experimental and theoretical results demonstrate that the N/P coordinated Co sites enable optimized charge distribution and facilitate oxygen intermediate adsorption/desorption. Such a CoSA/NPC catalyst exhibits high oxygen reduction reaction (ORR) activity with a half-wave potential (E1/2) of 0.87 V and oxygen evolution reaction (OER) activity with a low potential of 1.67 V at 10 mA cm−2. As an air electrode in ZABs, it demonstrates a high peak power density of 204.3 mW cm−2 and excellent long-term stability in aqueous ZABs. It also reveals superior flexibility and stability in solid-state ZABs. Thus, CoSA/NPC is a promising bifunctional electrocatalyst for practical applications in aqueous and flexible solid-state ZABs.

Atomically dispersed metal catalysts are promising candidates for the oxygen reduction reaction (ORR) and for achieving efficient energy conversion. However, rational design of single atom catalysts (SACs) with high-efficiency ORR catalytic activity and superior stability is still crucial yet challenging. Herein, an in situ gas-foaming methodology is presented for constructing single Fe atoms dispersed on a N, S-codoped (FeSA/NSC) hierarchically ordered porous carbon (HOPC) framework via one-step pyrolysis of dopamine (DA)/Fe3+ complexes and thiourea in SBA-15 channels. HOPC structures (facilitating active site access and mass transfer) and optimized FeN4S2 catalytic centers make FeSA/NSC exhibit high ORR activity with a half-wave potential (E1/2) of 0.91 V, fuel selectivity and long-term stability (3 mV negative shift after 5000 potential cycles) in 0.1 M KOH. It even shows comparable ORR catalytic activity (E1/2 = 0.78 V) to the Pt/C catalyst in acidic electrolytes. As the air electrode in zinc–air batteries, FeSA/NSC demonstrates superior power density, long-term discharge stability and specific capacity to the commercial Pt/C catalyst. Thus, FeSA/NSC is a promising non-platinum-group metal ORR catalyst for the ORR and application in zinc–air batteries.

In this work, chlorine doped Bi–BiO2−x (Cl–Bi–BiO2−x) was prepared by a one-step solvothermal method using sodium bismuthate (NaBiO3·2H2O) as a Bi source without the addition of a surfactant. Both time and temperature of solvothermal reaction may regulate the amount of Bi0 deposition in the photocatalyst, causing surface plasmon resonance (SPR) and oxygen vacancy defects (OVDs). The synergistic effect of SRP and OVD promotes the separation of photogenerated electron–hole pairs, shortens the bandgap, and enhances the optical absorptivity. Imidacloprid, a widely used insecticide, was selected to explore such photocatalysts with controlled OVD and SPR for potential application in pesticide photo-degradation in aqueous solution. Cl–Bi–BiO2−x with a rationally coordinating OVD and SPR shows a narrower band gap, wider light absorption, higher separation efficiency of photo-generated charges and faster pollutant degradation, supporting a green method to synthesize bismuth-based photocatalysts and facilitating the study on the synergistic effect of SPR and OVD on photocatalysts.

Phenolic-metal complexation coatings have been discovered to be a universal route for the deposition of multifunctional coatings. However, most complexation coatings have been prepared by the immersion method, which limits their practical large-scale application. Herein, we describe a facile and green engineering strategy that involves spraying phenolic compound and metal ions on substrate to form in-situ complexation coating with different coordination states. The coating is formed within minutes and it can be achieved in large scale by the spray method. The pyrogallol-FeIII complexation coating is prepared at pH 7.5, which consists predominantly of biscoordination complexation with a small amount of tris-coordination complexation. It displays that the water contact angle is near zero due to the generation of rough hierarchical structures and massive hydroxyl groups. The superhydrophilic cotton resulting from the deposition of the pyrogallol-FeIII complexation can separate oil/water mixtures and surfactant-stabilized oil-in-water emulsions with high separation efficiency. The formation of the phenolic-metal complexation coating by using spray technique constitutes a cost-effective and environmentally friendly, strategy with potential to be applied for large-scale surface engineering processes and green oil/water separation.

Photocatalysis with universality and feasibility has been widely applied to degrade pollutants that mainly exist in gas and liquid systems. However, the photocatalytic degradation of contaminants on solid surfaces is rarely reported. The investigation of the photocatalytic degradation mechanism of pesticide on a solid surface will provide a vital reference for removing pesticide residues on fruit surfaces. Here, we discovered that in situ photocatalytic degradation on solid surface (PDSS) is a moisture dependent process regulated by the interaction between TiO2 and H2O. The interaction mechanism between TiO2 and moisture was revealed by X-ray photoelectron spectroscopy and in situ FT-IR. Meanwhile, we investigated a water layer formed between TiO2 and water on the surface by density functional theory. The photocatalytic degradation process of imidacloprid on the solid surface is proposed. This work explores the H2O impact on photocatalysis in solid surfaces and provides a significant reference for removing pesticide residues in realistic environmental conditions.

The wettability of the coating used in controlled release fertilizers (CRFs) is a crucial parameter for the release behavior of nutrients. However, how to control the wettability of coating to tune nutrient release is a big challenge. Herein, the alkylamine-poly (tannic acid) (APTA) building blocks coatings with controlled wettability were prepared as coating materials for CRFs. Alkylamine (octadecylamine (ODA), hexadecylamine (HDA), dodecylamine (DDA), and hexylamine (HEA)) were applied for the modification of poly (tannic acid) (PTA) coating on the silicon wafer and urea surface. The wettability of coatings on silicon wafers were studied and nutrient release of APTA coated fertilizers were characterized in water and soil. The nitrogen nutrient and water vapor permeability coefficient of coatings were characterisized and the mathematical model for predicting the release of nutrients in soil. The alkyl chain length of alkylamine is demonstrated to play a crucial part in controlling the wettability. The rate of nutrient release increases in the order of ODA-PTA

Polymer coated fertilizer has been designed for gradual release of nutritional content of fertilizer to improve the utilization efficiency. However, the better slow release property of the coated fertilizer and simplified preparation process are still a huge challenge. The hydrophobic ODA-polyphenol film coated urea was prepared by one-step spraying for excellent nutrient release performance. Octadecylamine (ODA) was used to modify poly(tannic acid) (PTA) and poly(pyrogallol) (PPG) coating on substrates and prepare the hydrophobic ODA-PTA and ODA-PPG coated urea granules. The nutrient release rate of ODA-PTA and ODA-PPG coated fertilizers was much slower than PTA and PPG coated fertilizers in water and soil. The N release longevities of ODA-PTA coated fertilizers will be extended from 2 h to 30 days compared with PTA coated fertilizers. Moreover, pot experiments showed that coated fertilizer could effectively promote plant growth. This work will provide one-step spraying co-deposition approach to fabricate hydrophobic ODA-polyphenol film coated urea to improve the N release longevity, which can shine a light on the development of new slow release fertilizers (SRFs).

Dopamine (DA) polymerization has received significant attention in many fields, however, almost all of the works are limited to aqueous solution and hamper its wide application. This paper reports that amines can trigger DA polymerization by capturing the H+ from DA hydrochloride and intermediates to accelerate the generation of radical species in water or organic solvents. Increasing concentration and decreasing pKb of amines cause the reaction equilibrium to shift toward the product polydopamine (PDA). Water-soluble and easily-removable Na2 SO4 nanowires and NaCl cubes can be used as templates to prepare different morphologies of hollow PDA structures by DA polymerization in ethanol solution. The carbonization production of PDA nanotubes at 900 °C (PDNC-900) is obtained and demonstrates electrochemical activity in the oxygen reduction reaction that is comparable to that of Pt/C.