Promotional effect of embedded Ni NPs in alginate-based carbon toward Pd NPs efficiency for high-concentration p-nitrophenol reduction.

Noble metal-based catalytic material with maximum utilization is of prime attraction for conserving rare metal resources. Herein, highly dispersion Ni nanoparticles (NPs)-modified N-doped mesoporous carbon material (Ni-N@C) was fabricated by pyrolysis of Ni2+/Histidine cross-linked alginate hydrogels. In a step forward, the obtained Ni-N@C nanocatalyst was treated by the solution of Pd2+, and tiny amount of Pd NPs were deposited on the surface of Ni via the reducibility of Ni to achieve the high dispersion of precious metals material. In the degradation of highly-concentration p-nitrophenol, the catalyst presents excellent performance which could completely degrade pollutants within a very short period. It was demonstrated that pre-embedded Ni NPs could not only increase the efficiency of Pd NPs but also endow the facile separation characteristic to the catalyst. Besides, the catalyst maintained favorable catalytic capacity even after five reaction cycles. In brief, this work may provide novel guidance for the maximum utilization of noble metal-modified mesoporous N-doped carbon-supported catalysts in practical applications of industrial and the treatment highly-concentration p-nitrophenol.