Functionalization of graphitic carbon nitride/ZnO heterojunctions with zinc cyanamide groups: A powerful approach for photocatalytic degradation of anticancer drugs Pérez Molina, Álvaro Morales Torres, Sergio Maldonado Hodar, Francisco José Pastrana Martínez, Luisa María This work was financially supported by Junta de Andalucía - Conserjería de Universidad, Investigación e Innovación - Project (P21_00208) and by ref. PID2021-126579OB-C31 by MICIU/AEI/10.13039 /501100011033 and ERDF "A way of making Europe". Á.P.-M and S.M.-T. are grateful to MICIN/AEI/10.13039/501100011033 and FSE “El FSE invierte en tu futuro” for the predoctoral (PRE2019-087946) and Ramon y Cajal (RYC-2019-026634-I) research contracts, respectively. “Unidad de Excelencia Química Aplicada a Biomedicina y Medioambiente” of the University of Granada (UEQ-UGR) is gratefully acknowledged for the technical assistance. Graphitic carbon nitride/zinc oxide composites (CN/ZnO) were innovatively synthesized via a one-pot thermal treatment of a mixture of melamine and different zinc salts (zinc acetate, zinc nitrate, zinc sulfate, and zinc chloride) as the precursor of CN and ZnO, respectively. Composites derived from acetate, nitrate or sulfate showcased hexagonal ZnO wurtzite phase, while those prepared with zinc chloride revealed a unique secondary phase identified as tetragonal zinc cyanamide (ZnNCN). This novel phase formation was fine-tuned by optimizing synthesis conditions, including temperature ranging from 450 to 650 °C and metal salt loading between 25 and 75 wt.%. Photocatalytic testing for the degradation of cyclophosphamide (CP) and 5-fluorouracil (5-FU) under near UV-Vis irradiation, highlighted the standout performance of the composite synthesized with 75 wt.% zinc chloride at 550 °C, labelled C-75-550. This composite delivered superior activity, attributed to enhanced pollutant adsorption and the suppression of electron-hole recombination due to the synergistic interplay of CN, ZnO, and ZnNCN. Furthermore, C-75-550 exhibited remarkable stability across multiple cycles, bolstered by Zn–N bond stabilization. Advanced analysis using UHPLC-MS, coupled with reactive species scavenger studies, allow to propose several pathways for the photodegradation of 5-FU, underscoring the composite transformative potential in environmental remediation 2025-04-30T06:31:59Z 2025-04-30T06:31:59Z 2025-03 journal article Published version: Pérez-Molina, Á. et al. Separation and Purification Technology , 2025, 364, 132306. https://doi.org/10.1016/j.seppur.2025.132306 https://hdl.handle.net/10481/103849 10.1016/j.seppur.2025.132306 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier