Intense Visible-Light Absorption in SrRuO(3)/C(3)N(4) Heterostructures for the Highly Efficient Reduction of Hg(II)

[Image: see text] Strontium ruthenium oxide (SrRuO(3)) is recognized as a metallic itinerant ferromagnet and utilized as a conducting electrode in heterostructure oxides with unforeseen optical characteristics, including remarkably low-reflection and high-absorption visible-light spectrum compared to classical metals. By coupling mesoporous SrRuO(3) nanoparticles (NPs) with porous g-C(3)N(4) nanosheets for the first time, we evidence remarkably promoted visible light absorption and superior photocatalytic performances for Hg(II) reduction under illumination with visible light. The photocatalytic performance of g-C(3)N(4) increased upon boosting the SrRuO(3) percentage to 1.5%, and this (1.5% SrRuO(3)/g-C(3)N(4) heterostructure) is considered the optimum condition to obtain a high photocatalytic efficiency of about 100% within 50 min. It was promoted 3.68 and 5.75 times compared to SrRuO(3) and g-C(3)N(4), respectively. Also, a Hg(II) reduction rate of 1.5% SrRuO(3)/g-C(3)N(4) was enhanced3.84- and 6.28-fold than those of pure SrRuO(3) NPs and g-C(3)N(4), respectively. Such a high photocatalytic performance over SrRuO(3)/g-C(3)N(4) photocatalysts was explained by the characteristics of SrRuO(3) NPs incorporated on porous g-C(3)N(4) layers, which demonstrate strong absorption of visible light with a narrow band gap, a large photocurrent density of ∼9.07 mA/cm(2), well-dispersed and small particle sizes, and cause facile diffusion of HCOOH and Hg(II) ions and electrons. The present work provides a dramatic novel approach to the challenge of constructing visible-light photosensitive photocatalysts for wastewater remediation.