Boosting CO2 piezo-reduction via metal-support interactions in Au/ZnO based catalysts.

Confronting the challenge of climate change necessitates innovative approaches for the reduction of CO2 emissions. Metal-support interaction has been widely demonstrated to enable greatly improved performances in thermal-catalytic, photocatalytic and electrocatalytic CO2 reduction. However, its applicability and specifically its role in the emerging piezo-electrocatalytic CO2 reduction are unknown, severely hampering the utilizations of piezo-electrocatalysis in CO2 conversion. Herein, by adopting Au particles supported on ZnO (Au/ZnO) as a paradigm, it is found that the metal-support interaction can remarkably improve the separation and transfer of piezo-carriers and enhance CO2 adsorption. As a result, Au/ZnO demonstrates a substantially boosted activity for piezo-electrocatalytic CO2 reduction and the optimal sample exhibits a 37.3% increase in CO yield compared to the pristine ZnO. The integration of metal-support interactions opens a new avenue to the design of advanced piezo-electrocatalysts for CO2 reduction.

Strong Tribocatalytic Nitrogen Fixation of Graphite Carbon Nitride g-C3N4 through Harvesting Friction Energy.

Mechanical energy derived from friction is a kind of clean energy which is ubiquitous in nature. In this research, two-dimensional graphite carbon nitride (g-C3N4) is successfully applied to the conversion of nitrogen (N2) fixation through collecting the mechanical energy generated from the friction between a g-C3N4 catalyst and a stirring rod. At the stirring speed of 1000 r/min, the tribocatalytic ammonia radical (NH4+) generation rate of g-C3N4 can achieve 100.56 µmol·L-1·g-1·h-1 using methanol as a positive charge scavenger, which is 3.91 times higher than that without any scavengers. Meanwhile, ammonia is not generated without a catalyst or contact between the g-C3N4 catalyst and the stirring rod. The tribocatalytic effect originates from the friction between the g-C3N4 catalyst and the stirring rod which results in the charges transfer crossing the contact interface, then the positive and negative charges remain on the catalyst and the stirring rod respectively, which can further react with the substance dissolved in the reaction solution to achieve the conversion of N2 to ammonia. The effects of number and stirring speed of the rods on the performance of g-C3N4 tribocatalytic N2 fixation are further investigated. This excellent and efficient tribocatalysis can provide a potential avenue towards harvesting the mechanical energy in a natural environment.