Photoactive Brownmillerite Multiferroic KBiFe2O5 and Its Potential Application in Sunlight-Driven Photocatalysis

KBiFe2O5 (KBFO) is an upcoming promising brownmilleritestructured multiferroic photoactive material for next-generation photovoltaic and photocatalytic applications. In the present work, KBFO has been developed using multistep thermal treatment method to reduce the volatility of constituent
elements and improve the stability of compound. The band gap of KBFO (found to be ∼1.68 eV) extends to the near-infrared region compared to traditional perovskite-structured multiferroics. The magnetic and dielectric transitions occur
in the same temperature range (740 K−800 K), reflecting the existence of magneto-dielectric effect in the as-synthesized sample. It also shows promising photocatalytic activity by degrading organic effluents under natural sunlight
compared to regular perovskite BiFeO3 photocatalyst (operating under visible light). A new application of brownmillerite multiferroic KBFO photocatalyst in environmental and energy applications has been explored by integrating the structural, optical, magnetic, and dielectric properties of the same.