This book contains six chapters that detail advances in energy research. Chapter one provides recent developments in Pnictogen semimetal (Sb, Bi)-based selenides, as well as various two-dimensional (2D) TMDC materials and fundamentals of photoelectrochemical (PEC) water splitting. Chapter two describes the findings of recent research on the generation of a hydrogen-based synthesis gas obtained from water electrolysis that uses an added carbon source, where the DC electric power comes from a renewable source such as wind or solar energy. Chapter three analyzes the energy balance and carbon global equilibria involving Earth and its atmosphere. Chapter four explores how to enhance the efficiency of dual-fuel, low-emission combustion chambers in gas turbine engines. Chapter five discusses the effectiveness of the reinforcing elements used for developing technology of construction 3D printing, and it studies the existing features of automation and robotization in additive construction technologies. Chapter six delves into the intricacies of Carbazole-Based HTLs within the contexts of OLEDs and PSCs.