Charge state modulation on boron site by carbon and nitrogen localized bonding microenvironment for two-electron electrocatalytic H_(2)O_(2)production

Design of electrochemical active boron(B)site at solid materials to understand the relationships between the localized structure,charge state at the B site and electrocatalytic activity plays a crucial role in boosting the green electrochemical synthesis of hydrogen peroxide(H_(2)O_(2))via two-electron oxygen reduction(2eORR)pathway.Herein,we demonstrate a carbon(C)and nitrogen(N)localized bonding microenvironment to modulate the charge state of B site at the boron-carbon nitride solid(BCNs)to realize the efficient selective electrocatalytic H_(2)O_(2)production.The localized chemical structure of N-B-N,N-B-C and C-B-C bonds at B site can be regulated through solid-state reaction between boron nitride(BN)and porous carbon(C)at variable temperatures.The optimized BCN-1100 achieves an outstanding H_(2)O_(2)selectivity of 89%and electron transfer number of 2.2(at 0.55 V vs.RHE),with the production of 10.55mmol/L during 2.5 h and the catalytic stability duration for 15000 cycles.Further first-principles calculations identified the dependency of localized bonding microenvironment on the OOH~*adsorption energies and relevant charge states at the boron site.The localized structure of B site with BNC_(2)-Gr configuration is predicted to be the highest 2eORR activity.

Enhanced photocatalytic performance of SrTiO_(3) powder induced by europium dopants

In this work,Eu^(3+)doped SrTiO_(3)powders were synthesized by sol-gel method and the influences of Eu^(3+)dopants on the crystalline structure,micro structure mo rphology,electronic band-gap and photocatalytic performance for degradation of o rganic pollutant were investigated in detail.Research results reveal that the incorporated Eu^(3+)ions in SrTiO_(3)lattice are preferable to substitute the Sr^(2+)-Ti^(4+)ions pair by two Eu^(3+)ions.The presence of Eu^(3+)ions plays a significant role for the microstructure morphology of the S rTiO_(3)powders,leading to the formation of smaller size nanoparticles with a higher specific surface area.The light absorption capability of the resulting materials is improved owing to the narrowing of the band-gap induced by Eu^(3+)dopants.As a result,the enhanced photocatalytic activity application for photodegradation of Rhodamine B solution is demonstrated for the SrTiO_(3)powders doped with Eu^(3+)ions.