Computational Design of Single Mo Atom Anchored Defective Boron Phosphide Monolayer as a High-performance Electrocatalyst for the Nitrogen Reduction Reaction

Catalytic reduction of molecular dinitrogen(N_(2))to ammonia(NH_(3))is one of the most important and challenging industrial reactions.Electrochemical reduction is considered as an energy-saving technology for artificial ambient nitrogen fixation,which is emerging as an optimal potential sustainable strategy to substitute for the Haber–Bosch process.However,this process demands efficient catalysts for the N_(2)reduction reaction(NRR).Here,by means of first-principles calculations,we systematically explored the potential electrocatalytic performance of single transition metal atoms(Pd,Ag,Rh,Cu,Ti,Mo,Mn,Zn,Fe,Co,Ru,and Pt)embedded in monolayer defective boron phosphide(TMs/BP)monolayer with a phosphorus monovacancy for ambient NH_(3)production.Among them,the Mo/BP exhibits the best catalytic performance for ambient reduction of N_(2)through the typical enzymatic and consecutive reaction pathways with an activation barrier of 0.68 e V,indicating that Mo/BP is an efficient catalyst for N_(2)fixation.We believe that this work could provide a new avenue of ambient NH_(3)synthesis by using the designed single-atom electrocatalysts.

Hollow TiO2-x porous microspheres composed of wellcrystalline nanocrystals for high-performance lithiumion batteries

Hollow TiO2-x porous microspheres consisted of numerous well-crystalline nanocrystals with superior structural integrity and robust hollow interior were synthesized by a facile sol-gel template-assisted approach and two-step carbonprotected calcination method, together with hydrogenation treatment. They exhibit a uniform diameter of -470 nm with a thin porous wall shell of -50 nm in thickness. The Brunauer-Emmett-Teller （BET） surface area and pore volume are -19 m2/g and 0.07 crnB/g, respectively. These hollow TiOR_x porous microspheres demonstrated excellent lithium storage performance with stable capacity retention for over 300 cycles （a high capacity of 151 mAh/g can be obtained up to 300 cycles at I C, retaining 81.6% of the initial capacity of 185 mAh/g） and enhanced rate capability even up to 10 C （222, 192, 121, and 92.1 mAh/g at current rates of 0.5, 1, 5, and 10 C, respectively）. The intrinsic increased conductivity of the hydrogenated TiO2 microspheres and their robust hollow structure benefidal for lithium ion-electron diffusion and mitigating the structural strain synergistically contribute to the remarkable improvements in their cycling stability and rate performance.

Interfacial synthesis of crystalline quasi-two-dimensional polyaniline thin films for high-performance flexible on-chip micro-supercapacitors

Quasi-two-dimensional(q2 D)conducting polymer thin film synergizes the advantageous features of longrange molecular ordering and high intrinsic conductivity,which are promising for flexible thin film-based micro-supercapacitors(MSCs).Herein,we present the high-performance flexible MSCs based on highly ordered quasi-two-dimensional polyaniline(q2 D-PANI)thin film using surfactant monolayer assisted interfacial synthesis(SMAIS).Owing to high electrical conductivity,rich redox chemistry,and thin-film morphology,the q2 D-PANI MSCs show high volumetric specific capacitance(ca.360 F/cm^(3))and energy density(17.9 m Wh/cm^(3)),which outperform the state-of-art PANI thin-film based MSCs and promise for future flexible electronics.