Using sodium D-gluconate to suppress hydrogen production in wet aluminium waste dust collection systems

Simultaneously Tailoring Zinc Deposition and Solvation Structure by Electrolyte Additive

Aqueous zinc ion batteries (AZIBs) have attracted intense attention due to their high safety and low cost. Unfortunately, the serious dendrite growth and side reactions of the Zn metal anode in an aqueous electrolyte result in rapid battery failure, hindering the practical application of AZIBs. Herein, sodium gluconate as a dual-functional electrolyte additive has been employed to enhance the electrochemical performance of AZIBs. Gluconate anions preferentially adsorb on the surface of the Zn anode, which effectively prevents H2 evolution and induces uniform Zn deposition to suppress dendrite growth. Moreover, the gluconate anions can highly coordinate with Zn2+, promoting the dissolution of [Zn(H2O)6]2+ to inhibit side reactions and the water-induced corrosion reaction. As a result, the Zn||Zn symmetric battery exhibits a long-term cycling stability of over 3000 h at 1 mA cm-2/1 mA h cm-2 and 600 h at 10 mA cm-2/10 mA h cm-2. Furthermore, the NH4V4O10||Zn full battery also displays excellent cycling stability and a high reversible capacity of 193 mA h g-1 at 2 A g-1 after 1000 cycles. Given the low-cost advantage of SG, the proposed interface chemistry modulation strategy holds considerable potential for promoting the commercialization of AZIBs.

Inerting Waste Al Alloy Dust with Natural High Polymers: Sustainability of Industrial Waste

A large amount of waste dust will be produced in the process of metal grinding, resulting in a waste of resources and environmental pollution. Therefore, we present a new method of inerting waste aluminum (Al) alloy dust for recycling purposes. Three natural high polymers-starch, pectin, and hydroxypropyl cellulose-were selected to inert waste metal dust in order to prevent the alloy from hydrolyzing and keep the dust pure enough for reuse. The particles of the Al base alloy before and after dust reaction were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infra-red (FTIR), and the relevant reaction mechanism was clarified. The hydrogen evolution test indicated that, across the temperature interval of 313-333 K, 0.75 wt% pectin inerted hydrogen evolution most efficiently (90.125%). XRD analysis indicated that the inerted product is composed of Al monomer and Al₃Mg₂, with no detectable content of Al hydroxide. The purity of the Al alloy dust was preserved. SEM and FTIR analyses indicated that the -OH, -COOH, and -COOCH₃ functional groups in the high polymer participated in the coordination reaction by adsorbing on the surface of the waste Al alloy particles to produce a protective film, which conforms to Langmuir's adsorption model. Verification of the inerted Al alloy dust in industrial production confirmed the possibility of reusing waste Al alloy dust. This study provides a simple and effective method for recycling waste Al alloy dust.

Hydrogen Inhibition as Explosion Prevention in Wet Metal Dust Removal Systems

Hydrogen energy attracts an amount of attention as an environmentally friendly and sustainable energy source. However, hydrogen is also flammable. Hydrogen fires and explosions might occur in wet-dust-removal systems if accumulated aluminum dust reacts with water. Hydrogen inhibition is a safe method to address these issues. For this purpose, we used sodium citrate, a renewable and nontoxic raw material to inhibit H2 formation. Specifically, hydrogen inhibition experiments with sodium citrate were carried out using custom-built equipment developed by our research group. When the concentration of sodium citrate solution was in the range of 0.4–4.0 g/L, a protective coating was formed on the surface of the Al particles, which prevented them from contacting with water. The inhibitory effect was achieved when the concentration of sodium citrate was in a certain range, and too much or too little addition may reduce the inhibitory effect. In this paper, we also discuss the economic aspects of H2 inhibition with this method because it offers excellent safety advantages and could be incorporated on a large scale. Such an intrinsic safety design of H2 inhibition to control explosions in wet-dust-removal systems could be applied to ensure the safety of other systems, such as nuclear reactors.

Flexible fiber-shaped hydrogen gas sensor via coupling palladium with conductive polymer gel fiber

Rational design of fiber-shaped gas sensors with both excellent mechanical properties and sensing performance is of great significance for boosting future portable and wearable sensing electronics, however, it is still a challenge. Herein, we develop a novel fiber-shaped hydrogen (H₂) sensor by directly electrochemically growing palladium (Pd) sensing layer on conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fiber electrode. This approach produces free-standing functional fiber (PEDOT:PSS@Pd) with promising mechanical features of flexibility, light weight, knittability and high mechanical strength, and good H₂ sensing performance at room temperature. The PEDOT:PSS@Pd fiber sensor exhibits short response time of 34 (± 6) s@1% and 19 (± 4) s@4% H₂ and excellent cycling stability. In addition, the fiber sensor remains good sensing behavior under different mechanical bending states, showing potential for constructing wearable sensor devices for timely H₂ leak detection. Therefore, this work has provided a smart design strategy of fiber-based gas sensor, offering an effective sensing platform and is believed to stimulate the development of wearable electronics.