Chromium phosphide nanoparticles embedded in porous nitrogen-/phosphorus-doped carbon as efficient electrocatalysts for a nitrogen reduction reaction

The resource recovery of heavy metals from effluent has significant environmental implications and potential commercial value.Chromium phosphide nanoparticles embedded in a nitrogen-/phosphorus-doped porous carbon matrix(CrP/NPC)are synthesized via a consecutive Cr^(6+)leachate treatment and resource recovery process.Electrochemical testing shows that CrP/NPC shows excellent nitrogen reduction reaction(NRR)performance,which yields the highest NH_(3) production rate of 22.56μg h^(−1) mg^(−1)_(cat).and Faradaic efficiency(16.37%)at−0.5 V versus the reversible hydrogen electrode in a 0.05M Na_(2)SO_(4) aqueous solution,as well as robust catalytic stability.The isotopic experiments using ^(15)N^(2) as a nitrogen source confirm that the detected NH_(3) is derived from the NRR process.Finally,density functional theory(DFT)calculations show that the electron deficiency environment of the Cr site can significantly reduce the barrier of the NRR process and promote the formation of intermediate species.

Waste-yeast biomass as nitrogen/phosphorus sources and carbon template:Environment-friendly synthesis of N,P-Mo_(2)C nanoparticles on porous carbon matrix for efficient hydrogen evolution

Tailor-made advanced electrocatalysts with high active and stable for hydrogen evolution reaction(HER)play a key role in the development of hydrogen economy.Herein,a N,P-co-doped molybdenum carbide confined in porous carbon matrix(N,P-Mo_(2)C/NPC)with a hierarchical structure is prepared by a resources recovery process.The N,P-Mo_(2)C/NPC compound exhibits outstanding HER activity with a low overpotential of 84 mV to achieve 10 mA/cm^(2),and excellent stability in alkaline media.The electrochemical measurements confirm that the enhanced HER activity of N,P-Mo_(2)C/NPC is ascribe to the synergy of N,P-codoped and porous carbon matrix.Density functional theory calculations further reveal that the electron density of active sites on Mo_(2)C can be regulated by the N/P doping,leading to optimal H adsorption strength.In this work,the proof-of-concept resource utilization,a microorganism derived molybdenum carbide electrocatalyst for HER is fabricated,which may inaugurate a new way for designing electrocatalysts by the utilization of solid waste.