First study of phytosynthesis of TiO2 NPs using the leaf (KL), pod (KP), seed (KS) and seed shell (KSS) extracts of kola nut tree (Cola nitida) is herein reported. The TiO2 NPs were characterized and evaluated for their antimicrobial, dye degradation, antioxidant and anticoagulant activities. The nearly spherical-shaped particles had λmax of 272.5–275.0 nm with size range of 25.00–191.41 nm. FTIR analysis displayed prominent peaks at 3446.79, 1639.49 and 1382.96 cm−1, indicating the involvement of phenolic compounds and proteins in the phytosynthesis of TiO2 NPs. Both SAED and XRD showed bioformation of crystalline anatase TiO2 NPs which inhibited multidrug-drug resistant bacteria and toxigenic fungi. The catalytic activities of the particles were profound, with degradation of malachite green by 83.48–86.28 % without exposure to UV-irradiation, scavenging of DPPH and H2O2by 51.19–60.08 %, and 78.45–99.23 % respectively. The particles as well prevented the coagulation of human blood. In addition to the antimicrobial and dye-degrading activities, we report for the first time the H2O2 scavenging and anticoagulant activities of TiO2 NPs, showing that the particles can be useful for catalytic and biomedical applications.

Erosion corrosion performance of API 5L-X65 carbon steel was investigated at three different impingement velocities (3, 6 & 12 m/s), five different angles (15, 30, 45, 60, & 90°), and with/without solid particles (average particle size of 314 µm). The experiments were conducted in 0.2 M NaCl solution at room temperature for a duration of 24 h and the results showed that the maximum erosion corrosion rate was observed at 45° irrespective of the velocity. The highest erosion corrosion rate at 45° was due to the balance between the shear and normal impact stress at this angle. Ploughing, deep craters, and micro-forging/plastic deformation were found to be the main erosion corrosion mechanisms. The maximum wear scar depth measured using optical profilometery was found to be 51 µm (average) at an impingement angle of 45°.