**Abstract**

Titanium dioxide (TiO2) nanomaterials are very important for generating hydrogen through photoelectrochemical water splitting and remediation of environmental pollution. It has remained the focus of many researchers during last few decades due to their wide applications. Optical absorption properties of TiO2 can lead to increase their photocatalytic activities. However, its overall solar performance is very restricted because of its large bandgap. The emergence of black titania nanomaterials has recently triggered worldwide research interest due to its significantly improved solar absorption and enhanced photocatalytic performances. In this chapter, various synthetic approaches employed to obtain black titania are outlined, and the structural features of the black titania nanomaterials are described in detail, along with their photocatalytic performances towards various applications.

**Keywords:** black titania, chemical synthesis, hydrogen treatment, structural disorder, photocatalysis
