AbstractBiological methods for creating nanoparticles utilizing plant‐based extracts have generated considerable interest due to their desirable ecological characteristics when compared to chemical methods. In this, TiO2 NPs were synthesized from the waste of the Hordeum vulgare L. We employed various methods for characterizing our sample, including Ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction, Scanning electron microscopy, Energy dispersive X‐ray spectroscopy, thermogravimetric analysis, AFM, Dynamic light scattering and Zeta‐potential to confirm the TiO2 NPs (Titanium dioxide Nanoparticles) synthesis followed by biological applications such as anti‐microbial, and anti‐oxidant assays to confirm TiO2 NPs biological properties. The photocatalytic activity of the TiO2 nanoparticles was also studied followed by a full factorial method to understand the consequences of time, pH, and concentration on the dye degradation. Apart from this, the synthesized nanoparticles were also used to check the agricultural efficacy on Phaseolus vulgaris plant seed, where it was seen that the TiO2 nanoparticles not only enhanced the growth of the plant at lower concentrations but also enhanced the photosynthetic activity and chlorophyll, phenol and flavonoid content of it when compared to higher concentration and control. The molecular aspects (DNA) were also analyzed by gel electrophoresis to check the effect of TiO2 nanoparticles on the DNA of plants at different concentrations. Our study focuses on making the best use of the waste of Hordeum vulgare L. to synthesize biogenic TiO2 nanoparticles that can prove themselves to be one of the significant options for the industrial, agricultural, and biological world.