LaCoO3 nanorod immobilized waste egg shell: a nanocatalytic system for the reduction of water pollutants and direct amidation of esters

The production of catalytic materials from large-scale wastes represents an interesting way of sustainability which is largely untapped resource. The ‘waste into treasure’ turning strategy provides a possible way for synthesis of nanomaterial, having diverse environmental and industrial applications, in an eco-friendly way. Egg shell is abundantly available, cost-effective and renewable, possessing unique hierarchically porous structure which has been widely investigated in the field of adsorption, energy as well as catalysis. Herein, we are reporting a rationally fabricated LaCoO3 supported egg shell (LaCoO3/ES, LCES) using waste egg shell as template. The synthesized material was characterized using different techniques and used as nanocatalyst. The LaCoO3/ES catalyzed the reduction of 4-nitophenol (4-NP) to less toxic 4-aminophenol (4-AP) and methyl orange into its reduced less hazardous and decolorized product with high efficiency. Amides were also synthesized using base and solvent-free conditions via grinding showing increased catalytic performance. Therefore, the results obtained support a synergistic effect between cobalt and lanthanum ions that enhanced the catalytic activity for both reduction and amidation of esters. In the amidation series, a new product, namely N1, N3-bis(4-methylbenzyl) malonamide, was also synthesized. In addition, we were also able to successfully grow a single crystal of one of the compounds such as N-benzyl-2-cyanoacetamide and confirmed by Single Crystal X-ray Crystallography.