Biohybrid Organic Heterostructure Based on Chlorophyll-Bacteriochlorophyll Aggregates for Ecofriendly Hydrogen Production.

Hydrogen energy is an abundant, clean, sustainable and environmentally friendly renewable energy source. Therefore, the production of hydrogen by photocatalytically splitting water on semiconductors has been considered in recent years as a promising and sustainable strategy for converting solar energy into chemical energy to replace conventional energy sources and to solve the growing problem of environmental pollution and the global energy crisis. However, highly efficient solar-driven photocatalytic hydrogen production remains a huge challenge due to the poor visible light response of available photocatalytic materials and the low efficiency of separation and transfer of photogenerated electron-hole pairs. In the present work, organic heterojunction structures based on bacteriochlorophyll (BChl) and chlorophyll (Chl) molecules were introduced and used for solar-driven photocatalytic hydrogen production from water under visible light. Also, noble metal-free photocatalyst was successfully constructed on Ti3 C2 Tx nanosheets by simple successive deposition of Chl and BChl, which was used for the photocatalytic splitting water to hydrogen evolution reaction (HER). The results show that the optimal BChl@Chl@Ti3 C2 Tx composite has a high HER performance with 114 µmol/h/gcat , which is much higher than the BChl@Ti3 C2 Tx and Chl@Ti3 C2 Tx composites.

Charge Transfer, Change of the Spin Value, and Driving of Magnetic Order by Pressure in Bimetallic Molecular Complexes.

The magnetic bimetallic molecular-based compounds attract considerable attention because of their unique characteristics which are very different from those of traditional magnets. We demonstrate the effects of charge transfer as well as spin and magnetic order changes induced by high hydrostatic pressure applied to the two bimetallic multifunctional Prussian blue analogues, K0.1Co4[Fe(CN)6]2.7·18H2O and K0.5Mn3[Fe(CN)6]2.14·6H2O. Two opposite directions of change in their properties under pressure are revealed: (i) the magnetization reduction and magnetic order disappearing for the K0.1Co4[Fe(CN)6]2.7·18H2O compound and (ii) an increase of the magnetization and change of the sign of exchange coupling for the K0.5Mn3[Fe(CN)6]2.14·6H2O compound. It is a first observation of both the magnetic moment increase and transformation from ferrimagnetic order to ferromagnetic order that appear under pressure in Prussian blue analogues. The latter is explained by the charge transfer between the metallic ions resulting in the corresponding spin transitions.