In situ phthalocyanine synthesis chemistry in flames towards molecular fireproof engineering

Promoted Overall Water Splitting Catalytic Activity and Durability of Ni3Fe Alloy by Designing N-Doped Carbon Encapsulation

Combining an electrochemically stable material onto the surface of a catalyst can improve the durability of a transition metal catalyst, and enable the catalyst to operate stably at high current density. Herein, the contribution of the N-doped carbon shell (NCS) to the electrochemical properties is evaluated by comparing the characteristics of the Ni3Fe@NCS catalyst with the N-doped carbon shell, and the Ni3Fe catalyst. The synthesized Ni3Fe@NCS catalyst has a distinct overpotential difference from the Ni3Fe catalyst (ηOER = 468.8 mV, ηHER = 462.2 mV) at (200 and -200) mA cm-2 in 1 m KOH. In stability test at (10 and -10) mA cm-2, the Ni3Fe@NCS catalyst showed a stability of (95.47 and 99.6)%, while the Ni3Fe catalyst showed a stability of (72.4 and 95.9)%, respectively. In addition, the in situ X-ray Absorption Near Edge Spectroscopy (XANES) results show that redox reaction appeared in the Ni3Fe catalyst by applying voltages of (1.7 and -0.48) V. The decomposition of nickel and iron due to the redox reaction is detected as a high ppm concentration in the Ni3Fe catalyst through Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis. This work presents the strategy and design of a next-generation electrochemical catalyst to improve the electrocatalytic properties and stability.

Flame-responsive aryl ether nitrile structure towards multiple fire hazards suppression of thermoplastic polyester

Multiple fire hazards (heat, smoke, dripping) caused by thermoplastic polymers pose integrated risks. Halogen or phosphorus flame-retardants tend to increase toxic, smoke or dripping hazards due to their flame-retardant mechanism. The physical blending flame-retardants into matrixes also presents a migration dilemma with causing potential environmental threats. Herein, we propose a novel multi-hazards inhibition strategy by chemical-incorporating aryl ether nitrile structures into poly(ethylene terephthalate)(PET), which is a typical thermoplastic polymer and a major contributor of multiple fire hazards. Through flame-responsive cyclotrimerization and aliphatic fragment capture, the flammability risks and multi-hazards (heat, smoke, toxicity, dripping) are significantly suppressed. The limiting oxygen index of the modified PET increases from 21.0 to 31.0. The peak of heat release, total smoke release, and carbon monoxide production decrease by 49.0 %, 31.1 %, and 52.6 %, respectively. The dripping hazards are eliminated, and the UL-94 rating reaches to V-0 level with no dripping production. Hence, this state-of-art strategy supplies a new approach for the fire hazards suppression of thermoplastic polymers.