A novel exsolution technique-twice lasers: rapidly aroused explosive exsolution of nanoparticles to boost electrochemical performance.

The exsolution of nanoparticles (NPs) on material surfaces exhibits good performance with great potential in the field of catalysis. In this study, a method with twice lasers treatment (TLT) is proposed for the first time to rapidly promote the exsolution of Co NPs to the surface of (La0.7Sr0.3)0.93Ti0.93Co0.07O3(LSTC) by laser rapid heating to enhance the electrochemical performance of the LSTC. The entire process from precursor powder-stable perovskite crystal structure-Co NPs exsolution on the LSTC surface takes only ≈36 s by TLT. The Co NPs exsolution was confirmed by x-ray diffractometer, scanning electron microscopy and high-resolution transmission electron microscopy. After TLT, a large number of Co NPs reached 75 particlesµm-2appeared on the surface of LSTC with the onset potential of 1.38 V, the overpotential of 214 mV, and the Tafel slope of 81.14 mV dec-1, showing good catalytic activity and long-term stability. The novel process of using TLT to rapidly induce exsolution of NPs enables the rapid preparation of nanoparticle-decorated perovskite materials with better electrochemical properties, thus enriching exsolution technology and opening a new avenue for surface science research.

Nonreducing Ambient Atmosphere: Pulsed Electric Current Treatment of Co/Ni Doped Perovskite Oxides to Achieve Exsolution Enhanced Electrochemical Performance.

Exsolution of metal nanoparticles (NPs) on the surface of perovskite oxides is a promising approach for developing advanced catalytic materials through a "bottom-up" design strategy. Under a nonreducing ambient atmosphere utilizing pulsed electric current (PEC) treatment to promote the exsolution of perovskite oxides effectively overcomes the limitations inherent in conventional high-temperature vapor phase reduction (HTVPR) in situ exsolution methods. This paper presents the successful synthesis of (La0.7Sr0.3)0.8Ti0.93Ni0.07O3 (LSTN) perovskite oxide and (La0.7Sr0.3)0.8Ti0.93Co0.07O3 (LSTC) perovskite oxide using the sol-gel method, followed by PEC treatment at 600 V, 3 Hz, and 90 s. Utilizing various characterization techniques to confirm that PEC treatment can promote the exsolution of Co and Ni NPs under a nonreducing ambient atmosphere, the results indicated that the exsolved perovskite oxides exhibited significantly improved electrochemical properties. Furthermore, compared to the LSTN-PEC, LSTC-PEC demonstrates a lower onset potential of 1.504 V, a Tafel slope of 87.16 mV dec-1, lower impedance, higher capacitance, superior catalytic activity, and long-term stability.

A strategy for controlling degradation in vitro of carbon fiber-reinforced polylactic acid composites (by combining fiber modification and pulsed electromagnetic fields).

Carbon fiber-reinforced polylactic acid (C/PLA) composites are a human bone-fixation material, but control of the material's degradation remains a major factor hindering its widespread use. In this study, a combined method for controlling the degradation performance in vitro of C/PLA composites was designed. In this strategy, carbon fibers for C/PLA composite reinforcement were prepared in both modified and unmodified forms. A pulsed electromagnetic field (PEF) was then selectively applied during the subsequent degradation process. Results and analysis showed that the interfacial ester bonding between modified carbon fibers and PLA matrices significantly affected degradation in vitro of C/PLA composite. However, PEF affected the degradation performance of C/PLA composites and, after PEF treatment, the material's water absorption, mass retention, and bending and shearing strengths were changed to varying degrees. This method, by combining fiber modification and pulsed electromagnetic fields (abbreviated as CMP) provided a new strategy for the controlled degradation of C/PLA composites in human skeletal fixation.