**3. Conclusion**

Nowadays, because of the increasing population and demand for natural resources is a global concern, hence, it is one of the origins of environmental pollution. Among all the pollutants, lead is one of the most hazardous materials. For the reason that the toxic effect of lead in lead-based materials, the researcher communities and scientists concentrated on synthesized lead-free materials possessing the same properties. Since the last two decades, the investigation on such materials enhances unexpectedly. Lead-free perovskite materials with excellent dielectric and piezoelectric properties belonging to the ferroelectric family and these reduce the adverse effect on the human body as well as the environment. Here this chapter concludes with different applications like SOFCs, sensors, solar cells, wastewater treatment of lead-free perovskite materials.
