We selected a Eu³⁺ -containing tungstogermanate [(CH₃)₄N]_2.5H_7.5[Eu(GeW₁₁O₃₉)(H₂O)₂]₂·4.5H₂O (EuGeW) as a molecular dyad combining fluorescence and electroactivity components within the same framework and studied its electroswitchable fluorescence in solution and in the thin-film, which can be reversibly switched by electrochemical stimulation.

In recent years, due to the impact of global warming, environmental pollution, and the energy crisis, international attention and demand for clean energy are increasing. Hydrogen energy is recognized as one of the clean energy sources. Water is considered as the largest potential supplier of hydrogen energy. However, artificial catalytic water splitting for hydrogen and oxygen evolution has not been widely used due to its high energy consumption and high cost during catalytic cracking. Therefore, the exploitation of photocatalysts, electrocatalysts, and photo-electrocatalysts for rapid, cost effective, and reliable water splitting is essentially needed. Polyoxometalates (POMs) are regarded as the potential candidates for water splitting catalysis. In addition to their excellent catalytic properties and reversibly redox activities, POMs can also modify semiconductors to overcome their shortcomings, and improve photoelectric conversion efficiency and photocatalytic activity, which has attracted more and more attention in the field of photoelectric water splitting catalysis. In this review, we summarize the latest applications of POMs and semiconductor composites in the field of photo-electrocatalysis (PEC) for hydrogen and oxygen evolution by catalytic water splitting in recent years and take the latest applications of POMs and semiconductor composites in photocatalysis for water splitting. In the conclusion section, the challenges and strategies of photocatalytic and PEC water-splitting by POMs and semiconductor composites are discussed.

P ₅ W ₃₀ stabilized Au nanoparticles and graphene oxide were fabricated to form composite films exhibiting good electrocatalytic activity for H ₂ O ₂ reduction.

In this paper, we attempt to construct a simple and sensitive detection method for hydrogen peroxide based on reversible colour change and luminescence switching modulated by the electrochemical stimulation and redox reaction of H₂O₂ with electroreduced polyoxometalate. This method successfully combines the electrochromic and luminescent properties of the polyoxometalate to develop a novel detection method for H₂O₂ with good reversibility, which displays high sensitivity, a wide linear range and a low detection limit to H₂O₂ .