离子液体在生物工程方面的进展

离子液体具有不挥发性、非易燃性、离子电导率高、物化性能稳定、电化学窗口宽、结构多样性与可设计性等诸多优良特性,近年来已在电化学、生物、绿色化学等领域发挥着至关重要的作用。本文综述了离子液体在生物方面的一些应用：作为理想的载体将目标基因或者药物运送到靶细胞中达到治疗的目的;探究离子液体的毒性对生物体的影响从而达到杀灭癌细胞等特殊细胞或绿色降解的目的;利用其电催化活性好、灵敏度高等特性制成生物传感器用于电化学检测;将离子液体作为核酸分离的载体,使得核酸的分离的过程简化、效率提高。     

Single boron atom anchored on graphitic carbon nitride nanosheet (B/g-C2N) as a photocatalyst for nitrogen fixation: A first-principles study

It is essential to explore high efficient catalysts for nitrogen reduction in ammonia production. Based on the first-principles calculation, we find that B/g-C₂N can serve as high performance photocatalyst in N₂ fixation, where single boron atom is anchored on the g-C₂N to form B/g-C₂N. With the introduction of B atom to g-C₂N, the energy gap reduces from 2.45 eV to 1.21 eV and shows strong absorption in the visible light region. In addition, N₂ can be efficiently reduced on B/g-C₂N through the enzymatic mechanism with low onset potential of 0.07 V and rate-determining barrier of 0.50 eV. The "acceptance-donation" interaction between B/g-C₂N and N₂ plays a key role to active N₂, and the BN₂ moiety of B/g-C₂N acts as active and transportation center. The activity originates from the strong interaction between 1π1π^* orbitals of N₂ and molecular orbitals of B/g-C₂N, the ionization of 1π orbital and the filling of 1π^* orbital can increase the N≡N bond length greatly, making the activation of N₂. Overall, this work demonstrates that B/g-C₂N is a promising photocatalyst for N₂ fixation.     

Transition metal anchored on C9N4 as a single-atom catalyst for CO2 hydrogenation: A first-principles study

To alleviate the greenhouse effect and maintain the sustainable development, it is of great significance to find an efficient and low-cost catalyst to reduce carbon dioxide (CO₂) and generate formic acid (FA). In this work, based on the first-principles calculation, the catalytic performance of a single transition metal (TM) (TM = Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Cd, Ir, Pt, Au, or Hg) atom anchored on C₉N₄ monolayer (TM@C₉N₄) for the hydrogenation of CO₂ to FA is calculated. The results show that single TM atom doping in C₉N₄ can form a stable TM@C₉N₄ structure, and Cu@C₉N₄ and Co@C₉N₄ show better catalytic performance in the process of CO₂ hydrogenation to FA (the corresponding maximum energy barriers are 0.41 eV and 0.43 eV, respectively). The partial density of states (PDOS), projected crystal orbital Hamilton population (pCOHP), difference charge density analysis and Bader charge analysis demonstrate that the TM atom plays an important role in the reaction. The strong interaction between the 3d orbitals of the TM atom and the non-bonding orbitals (1π_g) of CO₂ allows the reaction to proceed under mild conditions. In general, our results show that Cu@C₉N₄ and Co@C₉N₄ are a promising single-atom catalyst and can be used as the non-precious metals electrocatalyst for CO₂ hydrogenation to formic acid.