The Effect of pH during Dissolution Process of Zinc Dross on Formation of Fe₂O₃/ ZnO/Bacterial Cellulose for Synthetic Dyes Remediation

In this study, zinc dross (ZD) was used as precursor to prepare hematite/zinc oxide (Fe 2 O 3 /ZnO) nanocomposites with bacterial cellulose (BC) as catalyst support to prevent agglomeration of the obtained Fe 2 O 3 /ZnO. pH during the dissolution process of ZD was varied at 4.2 and 5.5 (namely ZD4 and ZD5, respectively) to know the effect of pH on the formation of Fe 2 O 3 /ZnO/BC. As comparison, Fe 2 O 3 /ZnO from its pure precursor was also prepared with the same pH and Zn concentration of ZD4 and ZD5 (namely ZF4 and ZF5, respectively). Atomic absorption spectroscopy (AAS) results showed that Zn and Fe content in ZD4 sample (42,059 and 8,615 ppm, respectively) are higher than Zn and Fe content in ZD5 sample (25,554 and 2,204 ppm, respectively). X-ray diffraction (XRD) and Fourier transform infra-red (FTIR) results of all samples confirmed the successful synthesis and deposition of Fe 2 O 3 /ZnO on BC. Scanning electron microscope (SEM) results revealed that the average particle size of Fe 2 O 3 /ZnO/BC samples at pH 5.5 (341 nm for ZD5 and 385 nm for ZF5 samples respectively) are slightly smaller than samples at pH 4.2 (418 nm for ZD4 and 426 nm for ZF4 samples respectively). Photocatalytic activities results showed that Fe 2 O 3 /ZnO/BC samples at pH 5.5 (45.7% for ZD5 and 57.9% for ZF5 samples respectively) have slightly higher activity than samples at pH 4.2 (38.1% for ZD4 and 41.9% for ZF4 samples respectively). These findings demonstrate the potential use of ZD and suggest that dissolution of ZD at pH 5.5 led to smaller particles size and higher photocatalytic activity than pH 4.2.