Jianmin Chen,Qilu Yao,Jia Zhu,Xiangshu Chen,Zhang-Hui Lu
Bimetallic Rh–Ni nanoparticles (NPs) immobilized on the cerium hydroxide carbonate (Ce(OH)CO 3 ) have been successfully prepared by a facile co-reduction route, and characterized by XRD , SEM , TEM , EDX, ICP , XPS , and TG-DTA. The as-synthesized Rh–Ni/Ce(OH)CO 3 nanocomposites (NCs) with different metal compositions were applied as the highly efficient catalysts for hydrogen generation from the alkaline solution of hydrazine (N 2 H 4 ). Especially, the Rh 55 Ni 45 /Ce(OH)CO 3 NCs exerted the highly activity and 100% H 2 selectivity for the decomposition of hydrazine, providing high turnover frequency (TOF) values of 150 h −1 at 30 °C and 395 h −1 at 50 °C, respectively, relative high values for the metal catalysts . The activation energy for the decomposition of hydrazine catalyzed by Rh 55 Ni 45 /Ce(OH)CO 3 NCs was measured to be 38.8 kJ/mol, lower than most of the values reported for this reaction using many different catalysts. This excellent catalytic performance could be attributed to not only the strain and ligand effects between Rh and Ni, but also the strong interaction between RhNi NPs and Ce(OH)CO 3 support. Such a highly catalyst may greatly encourage the practical application of hydrazine as a hydrogen storage material.
This work reports the synthesis of a novel ( α / β- CdS)/Ce(OH)CO 3 composite featuring both heterojunction and heterogeneous junction structures via a simple injection titration-stirring method. The as-prepared composite exhibited excellent visible-light-driven photocatalytic activity for the degradation of high-concentration oxytetracycline (OTC) solution. Under optimal conditions determined by single-factor and response surface analyses, 0.0300 g of the composite achieved a 75.26% degradation efficiency for 50 mL of 160 mg/L OTC solution within 120 min of visible light irradiation. Notably, the composite demonstrated remarkable stability, retaining 62.39% of its initial activity after five cycles, and showed enhanced performance under real sunlight for 120 min, with a degradation rate of 78.50%. The improved photocatalytic performance is attributed to the uniform dispersion of CdS nanoparticles with abundant sulfur vacancies, which increase light absorption and facilitate charge carrier separation. Furthermore, the formation of direct Z -scheme heterojunctions and heterogeneous junctions between CdS and Ce(OH)CO 3 promotes efficient separation and transport of photogenerated carriers, thereby enhancing both photocatalytic activity and material stability.