Attractive Improvement in Structural, Magnetic, Optical, and Antimicrobial Activity of Silver Delafossite by Fe/Cr Doping

This paper presented a novel method of AgX O₂ (X = Fe or Cr) delafossite using flash auto-combustion technique. X-ray diffraction pattern (XRD) clarified single-phase structure. The morphology was analyzed by high-resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). The composition of the samples was determined using energy dispersive X-ray (EDX) analysis. The particle size estimated from HRTEM, FESEM, and XRD analyses revealed that the samples were in the nanoscale range. The magnetic hysteresis loop of the samples was measured at room temperature (300 K) and at low temperatures (200 and 100 K). Rare behavior by shifting the hysteresis loop horizontally was observed for AgCrO₂ delafossite at low temperatures (200 and 100 K). The optical properties were measured for the investigated samples. The antimicrobial study promoted that AgFeO₂ delafossite had a strong antibacterial activity against Gram-positive and Gram-negative bacteria than that of AgCrO₂ delafossite. However, no activity appeared for both samples against fungus micro-organisms. As a result, AgFeO₂ delafossite could be applied in cancer diagnoses, biomedical applications, and energy storage in solar cell. Moreover, AgCrO₂ delafossite could be applied as a photocathode in a dye-sensitized solar cell and biomedical applications.