New hydrothermal process for hierarchical TiO 2 nanostructures Arun Kumar Sinha, Subhra Jana, Surojit Pande, Sougata Sarkar, Mukul Pradhan, Mrinmoyee Basu, Sandip Saha, Anjali Pal and Tarasankar Pal* Electronic Supplementary Information ESI 1 Schematic representation for the formation of different shapes of TiO 2 nanocrystals R - H + (R) 4 Ti +4 R - [Ti(O 2 )(OH)(H 2 O) n ] + Aqueous [Ti(O 2 )(OH)(H 2 O) n ] + Pyridine or Triethylamine 100 w bulb H 2 O 100 w bulb Pyridine or Triethylamine Pyridine or Triethylamine 100 w bulb Pyridine or Triethylamine 100 w bulb H 2 O 100 w bulb Nanoflower on rough glass surface Nanopetal Nanopillar Nanopetal on smooth glass surface Nanorod Nanobundle 30% H 2 O 2 5% H 2 SO 4 100 w bulb Ti(SO 4 ) 2 -R - R - H + (R) 4 Ti +4 R - [Ti(O 2 )(OH)(H 2 O) n ] + Aqueous [Ti(O 2 )(OH)(H 2 O) n ] + Pyridine or Triethylamine 100 w bulb H 2 O 100 w bulb Pyridine or Triethylamine Pyridine or Triethylamine 100 w bulb Pyridine or Triethylamine 100 w bulb H 2 O 100 w bulb Nanoflower on rough glass surface Nanopetal Nanopillar Nanopetal on smooth glass surface Nanorod Nanobundle 30% H 2 O 2 5% H 2 SO 4 100 w bulb Ti(SO 4 ) 2 -R -