Evaluation of the alkyl chain length and photocatalytic antibacterial performance of cation g-C3N4

Several cation graphite carbon nitrides (g-C3N4-(CH2)n-ImI+) were synthesized by chemically attaching imidazolium appended alkane chains with different lengths (<i>n</i> = 2, 4, 8, 12 and 16) to g-C3N4. The introduction of a cation segment potentially improved the interaction between the carbon material and Gram negative (MDR-<i>A</i>. <i>baumannii</i>) and Gram positive (<i>S. aureus</i>) bacteria as characterized by <i>ζ</i> potential measurement. Short alkane chain (carbon numbers of 2, 4 and 8) carbon materials displayed relatively stronger bacterial interactions compared to long alkane chain bearing ones (<i>n</i> = 12 and 16). In addition, short chain carbon materials (g-C3N4-(CH2)4-ImI+) displayed relatively higher photocatalytic reactive oxygen species (¹O₂, ˙O₂^- and ˙OH) production efficiency. Bacterial interaction and ROS production efficiency synergistically contribute to photocatalytic antibacterial performance. The current data revealed that g-C3N4 with short flexible cations attached exhibited bacterial interaction and ROS production. Among these synthesized materials, g-C3N4-(CH2)4-ImI+ exhibited the most pronounced photocatalytic antibacterial efficiency (>99%).