Solar energy assisted synthesis of palladium nanoplates and its application in 2-phenoxy-1,1′-biphenyls and N,N-dimethyl-[1,1′-biphenyl] derivatives synthesis

•Triangular and Hexagonal Pd nanoplates are prepared using concentrated solar energy.•Optimum concentration ratio of sunlight and PVP helps for the nanoplates synthesis.•2-phenoxy-1,1′-biphenyls and N,N-dimethyl-[1,1′-biphenyl] derivatives are prepared.•One step, heterogeneous, recyclable, ligand free method with low catalyst loading.•The palladium nanoplates shows high TOF value (1940 h−1) and recyclability.

Present work aims to develop a greener approach for the palladium nanoplates (PdNPs) synthesis and its catalytic applications. The protocol deals with solar energy assisted ionic palladium reduction in the presence of polyvinylpyrrolidone (PVP) and ethylene glycol (EG) with a good shape selectivity. Polyvinylpyrrolidone plays a duel role of capping agent and mild reductant; whereas, ethylene glycol acts as a reductant and solvent. The optimum sunlight concentration is a key factor to the anticipated nanoplate's synthesis. Results show that the most of nanoparticles are hexagonal and triangular nanoplates in the range of 20–50 nm. This is a first report which shows ∼70% selectivity to the nanoplates formation using sun light. The study also covers it's catalytic application, wherein; 2-phenoxy-1,1′-biphenyls and N,N-dimethyl-[1,1′-biphenyl] derivatives were synthesized by a simple, ligand free, faster, one pot, ecological and economic protocol in aqueous medium. The catalyst shows better performance than that of conventionally available 10% Pd/C catalyst. The prepared PdNPs showed excellent catalytic performance to the desired products with recyclability.

Graphical abstractPalladium nanoplates have been synthesized with good shape selectivity by novel and green methodology using concentrated solar. The procedure employs solar energy for the reduction of ionic palladium in the presence of PVP and ethylene glycol. The essential slower reduction rate for nanoplates preparation has been obtained by adjusting the concentration ratio of sunlight with PVP. Along with capping effect PVP act as a mild reductant however, ethylene glycol as a reductant and solvent. The obtained nanoparticles consisting ∼70% of hexagonal and triangular nanoplates in the size range of 20–50 nm. The obtained PdNPs showing excellent catalytic performance in 2-phenoxy-1,1′-biphenyls and N,N-dimethyl-[1,1′-biphenyl] derivatives synthesis. The catalyst showing better performance than that of conventionally available 10% Pd/C catalyst. The synthesized nanoparticles could be recycled for three more consecutive recycles.Figure optionsDownload full-size imageDownload high-quality image (173 K)Download as PowerPoint slide