Recent advances regarding the implementation of 3D printing for solid oxide fuel cells, batteries, solar energy and environmental applications are reviewed.

Spectral up-conversion (UC) has been attracting growing interest for the effective harvesting of the near-infrared (NIR) part of sunlight for photocatalytic hydrogen production and environmental purification. We present evidence of NIR-to-UV-VIS photon conversion for degradation of organic dyes and hydrogen and oxygen evolution via water-splitting by TiO₂ and Rh–Cr oxide-loaded SrTiO₃:Al photocatalysts, respectively.

3D printing technology has become a powerful tool to produce 3D structures in any type of materials. In this work, 3D printing technology is used to produce 3D porous structures in CaSO₄ which can be later activated with an appropriate photocatalyst. TiO₂ was selected as an ideal photocatalyst producing activated 3D structures which can be used to study their effectiveness in the degradation of pollutants in wastewater. Methylene blue was used as a model molecule in these studies. The photocatalytic studies showed that TiO₂-activated 3D structures using nanoparticles of SiO₂ in the process produce more than 50% of conversion of methylene blue in just 1 h of irradiation and almost 90% in 5 h.