Construction of 2D up-conversion calcium copper silicate nanosheet for efficient photocatalytic nitrogen fixation under full spectrum

Abstract

Using clean and renewable solar energy to convert nitrogen to ammonia is promising, however the low utilization of light and the high cost of catalyst restrain its application. Herein, novel two-dimensional(2D) silicate CaCuSi 4 O 10 nanosheet was prepared by high-temperature solid state method using silica derived from palygorskite clay (Pal) and calcium carbonate derived from egg shells, respectively. The photocatalytic nitrogen fixation was performed using CaCuSi 4 O 10 compound as catalyst. The effect of flux content on the ammonia generation rate was investigated. Results demonstrated that the 2D CaCuSi 4 O 10 nanosheet can chemically adsorb and activate N 2 due to the high surface area along with abundant oxygen vacancies. The ammonia evolution rate of CaCuSi 4 O 10 can reach up to 60.3 μmol·g −1 ·h −1 and 15.6 μmol·g −1 ·h −1 under simulated solar light and near infrared (NIR) light irradiation, respectively. The enhanced photocatalytic nitrogen fixation can be ascribed to the up-conversion capability of CaCuSi 4 O 10 , which converts NIR into visible and UV light improving the utilization efficiency of full solar spectrum. Current study may offer a promising strategy for cost-effective photocatalytic nitrogen fixation under full spectrum. • 2D silicate CaCuSi 4 O 10 nanosheet prepared using mineral and biomass. • CaCuSi 4 O 10 compound owned abundant oxygen vacancies favoring N 2 activation. • Up-conversion capability of CaCuSi 4 O 10 improved solar energy utilization. • CaCuSi 4 O 10 nanosheet demonstrated cost-effective photocatalytic nitrogen fixation.