Efficient Photocatalytic Degradation of Pharmaceutical Residues with Ni-TiO2/gC3N4 Heterojunction

The proliferation of pharmaceutical residues in natural water systems has emerged as a significant environmental concern over the past decades. In response to these contaminants of emerging concern (CECs), our study introduces an innovative photocatalytic system, comprising Nickel (Ni)-doped Titanium Dioxide (TiO2) synergized with graphitic carbon nitride (gC3N4). This system demonstrated a notable 82.3% degradation efficiency of sodium salicylate, a precursor and active component of one of the most widely used medications (aspirin) in the world, within 4.5 hours. Utilizing the Central Composite Design and Response Surface Methodology (CCD/RSM), we optimized the Ni to TiO2 ratio, the gC3N4 to Ni-TiO2 proportion, and catalyst dosage. Detailed characterizations, including SEM, XRD, XPS, UV-VIS spectrophotometry, and electrochemical studies, revealed the catalyst's superior properties. Beyond sodium salicylate degradation, this system exhibits potential for broader organic pollutant remediation, presenting a promising avenue in wastewater treatment and environmental cleanup strategies.