Pd Shape-Controlled Nanoparticles Decorated with Metals for Electrochemical Nitrate and Nitrite Reduction

摘要

Nitrate (NO_3~-) pollution of groundwater occurs due to anthropogenic activities such as the overuse of nitrogen-rich agriculture fertilizers. Furthermore, nitrite (NO_2~-) causes adverse effects on human health such as methemoglobinemia ("blue baby syndrome") and cancer. Currently, physicochemical technologies such as reverse osmosis or ion exchange are used for nitrate removal, but these approaches are not sustainable as waste disposal of the brines remains a critical challenge (requiring the use of expensive post-treatment processes). Electrochemical NO_3~- remediation; however, offers several advantages when compared to physiochemical approaches for nitrate removal as NO_3~- is directly converted to harmless dinitrogen (N_2) gas resulting in no waste production. The main challenge with electrochemical NO_3~- reduction is the low activity and selectivity of the NO_3~- to N_2. The activity is limited by the rate-determining step (NO_(3(ads))~- to NO_(2(ads))~-) and selectivity is determined by the reduction of NO_(2(ads))~- to N_2 and/or ammonium (NH_4~+).