A Convenient Method to Prepare Novel Alkali Metal Potassium Doped Carbon Nitride Photocatalyst with Tunable Band Structure

Abstract

Nowadays, energy and environmental crisis are the great problems for all the countries in the world. With outstanding virtues, including non-pollution and inexhaustible supply, solar light is considered as one of the most promising candidate to resolve the energy crisis and environmental problems. However, low energy conversion efficiency still restricts its practical application. Recently, a metal-free visible-light photocatalyst graphitic carbon nitride (g-C 3 N 4) has attracted intensive interest for its many promising applications. The g-C 3 N 4 has a moderate band gap (2.7 eV), high chemical and thermal stability as well as fascinating electronic property. However, the rapid photogenerated electron-hole pair recombination leads to the low activity in practical applications 1,2. Several routes have been developed to solve this problem 3-6 , preparation of porous 7 g-C 3 N 4 , protonating by strong acids 8 and designing composite with other semiconductors 9. Among those strategies, doping is one of the most convenient and effective method. Yan et al. 3 prepared B doped g-C 3 N 4 and suggested that the enhanced degradation performance of Rhodamine-B was due to the improvement of dye adsorption and light absorption ability. Zhang et al. 4 synthesized phosphorus doped g-C 3 N 4 using ionic liquid [Bmim]PF 6 as phosphorus source. The obtained material exhibited significantly improved electrical conductivity and photocurrent. Noble metal, such as Pt, Pd and Ag, is an effective dopant to trap the