Construction of novel dual Z-scheme heterojunction of ternary CdS/g-C3N4/NiFe2O4 magnetically retrievable nanocomposite for boosted photocatalytic and energy storage applications

Abstract

A novel CdS/g-C3N4/NiFe2O4 (CGN) ternary nanocomposite photocatalyst was rationally developed via a simple wet-impregnation technique. Looking at the band structure of the components of the catalyst, a novel dual Z-scheme heterojunction can be successfully developed, generating more active sites that rapidly encourage the separation of the photo-generated species, contributes to preventing the aggregation of the synthesized nanocomposite, and enhance the light absorption efficiency. Remazol Brilliant Blue R (RBBR) was photocatalytically degraded by the nanocomposite in the presence of visible light to assess its photocatalytic effectiveness. The CGN 2 ternary nanocomposite had the maximum photocatalytic activity (96 %) if compared to the other prepared photocatalysts, as the rate of degradation of pure CdS, CdS/g-C3N4, CGN 1, and CGN 3 nanocomposites were only around 53.4, 85, 87.5, and 92 %, respectively, keeping the irradiation time. Based on trapping tests, •OH, •O2− and h+ radicals are the main active species that play a vital role in the photocatalytic oxidation process. Even after the fourth cycle, the CGN 2 composite remained efficient in the successive photocatalytic degradation of RBBR , maintaining over 91 % of its first degradation efficiency. The CdS/g-C3N4/NiFe2O4 nanocomposite revealed outstanding cycling stability due to its inherent magnetic property, making it a promising choice as a visible light photocatalyst. The electrochemical energy-storage behavior of CGN 2 as active electrode material exhibited a remarkable specific capacitance of 195 F g−1 (67 C g−1) at 1 A g−1. It delivered an outstanding cycling stability of 91 % capacity retention after 2000 charge–discharge cycles. The obtained remarkable results indicate that the CGN 2 nanocomposite is a promising active electrode material for high-performance energy-storage supercapacitors.