Impact of pyrolysis temperature on physicochemical properties of carbon nitride photocatalyst

Abstract

Polymeric carbon nitride (CN) materials are exigent in a wide variety of photocatalytic applications. Although CN has unique optoelectronic properties, poor surface area and limited light absorption are major bottlenecks in the exploration of CN photocatalysts. In this study, we present a facile template or patterning agent free route to high surface area CN scaffolds by varying the thermal pyrolysis temperature. As the pyrolysis temperature increased from 550 °C to 700 °C, a drastic improvement in visible light absorbance as well as surface area was noted. The photoactivity of the prepared material evaluated for visible-light induced dye degradation demonstrated that the pyrolysis temperature of CN governs its photocatalytic performance. A pyrolysis temperature of 680 °C was found to be sub-optimal to realize better optoelectronic properties. As prepared, high surface area materials were also used for low-pressure CO2 uptake studies, which again supplemented the excellent results for high temperature processed CN. Besides, the photoluminescence and electrochemical analysis indicate that high temperature pyrolysis significantly reduces charge carrier recombination of CN catalysts.