Two New Cu-Based Borates Catalyst with Cubic Supramolecular Cages for Efficient Catalytic Hydrogen Evolution

Focusing on the renewable energy, we devote to developping the efficient, robust and low cost water reduction catalysts (WRCs). Two new Cu-Based Borates catalyst with cubic supramolecular cages: H2Na2K2[(μ4-O)Cu4@ B20O32(OH)8]∙21H2O (1), and H2Rb1.6K2.4[(μ4-O)Cu4@B20O32 (OH)8]∙15H2O (2) were synthesized by hydrothermal condition. And the new copper complexes have applied as water reduction catalysts (WRCs) in the present of [Ir(ppy)2(dtbbpy)][PF6] as photosensitizer and triethanolamine (TEOA) as the sacrificial electron donor. Nevertheless, the main active place would attribute to the centre of Borates {Cu4@B20O32(OH)8}, and the atomic radius of counter cation would be the critical factor of the activity of photocatalytic. Increasing of atomic radius from Na atom to Rb atom, the activity of photocatalytic decrease efficiently. The experimental results match well with the conclusion of density functional theory (DFT). It is noteworthy that our research not only enrich the Cu-based Borate chemistry, but also investigate the photocatalytic activity of Cu-based Borate. This would guide us to synthesis Borates and develop their applications toward energy and environment.