No abstract

Water treatment, the hydrogen evolution reaction, and carbon capture are examples of the potential applications for solar photocatalysis. This has led to significant effort in the search for suitable heterogeneous catalysts. However, materials developed to-date often suffer from disadvantages such as charge recombination, low quantum efficiency, chemical instability, and poor economy of production/operation. These factors have made it difficult for the technology to develop beyond laboratory demonstrations. A potential solution to the problem lies with the appropriate design of the catalyst itself, particularly with respect to particle morphology. This review aims to highlight recent efforts directed towards the development and application of an anisotropic, bi-phasic heterodimer, or “Janus” catalyst. While the topic is in its relative infancy, it has been shown that a Janus morphology can improve catalyst performance by almost an order of magnitude. Hence, a systematic review has been undertaken to highlight and assess recent advances in this field. The review begins with the fundamentals of heterogeneous photocatalysis and proceeds to classify modern catalysts, including Janus particles. This is followed by a detailed description of the relevant studies involving Janus morphology and their demonstrated photocatalytic applications. Finally, an overview of the current challenges and future prospects is discussed along with a summary of the key highlights. It is observed that a Janus morphology can impart several intriguing advantages such as amplification of electric near-field and efficient charge separation. In order to unlock the full potential of Janus photocatalyst, further research in this direction is warranted.

A highly efficient third generation catalyst, CaCu3Ti4O12 (CCTO) shows excellent photoelectrochemical (PEC) and photocatalytic ability. As only 4% part of the solar spectrum covers UV light, thus it is highly desirable to develop visible light active photocatalyst materials like CCTO for effective solar energy conversion. A direct band transition with a narrow band gap (1.5 eV) was observed. Under light irradiation, high photocurrent density was found to be 0.96 mA/cm2, indicating the visible light induced photocatalytic ability of CCTO. Visible light mediated photocatalytic and photoelectrocatalytic degradation efficiency of CaCu3Ti4O12 pellets (CCTO) was investigated for three classes of pharmaceutical waste: erythrosin (dye), ciprofloxacin (antibiotic) and estriol (steroid). It is found that the degradation process follows first order kinetic reaction in electrocatalysis, photocatalysis and photoelectrocatalysis and high kinetic rate constant was observed in photoelectrocatalysis. This was quite high in comparison to previously reported methods.

Enhanced energy storage density by inducing defect dipoles in lead free relaxor ferroelectric BaTiO 3 -based ceramics Applied Physics Letters 110, 132902 (2017); 10.1063/1.4979467On the phase identity and its thermal evolution of lead free (Bi 1/2 Na 1/2 )TiO 3 -6 mol% BaTiO 3 Journal of Applied Physics 110, 074106 (2011); 10.1063/1.3645054Influence of structural evolution on energy storage properties in Bi 0.5 Na 0. With the advent of modern power electronics, embedded circuits and nonconventional energy harvesting, the need for high performance capacitors is bound to become indispensible. The current state-of-art employs ferroelectric ceramics and linear dielectrics for solid state capacitance. However, lead-free ferroelectric ceramics propose to offer significant improvement in the field of electrical energy storage owing to their high discharge efficiency and energy storage density. In this regards, the authors have investigated the effects of compressive stress as a means of improving the energy storage density of lead-free ferroelectric ceramics. The energy storage density of 0.91(Bi 0.5 Na 0.5 )TiO 3 -0.07BaTiO 3 -0.02(K 0.5 Na 0.5 )NbO 3 ferroelectric bulk ceramic was analyzed as a function of varying levels of compressive stress and operational temperature .It was observed that a peak energy density of 387 mJ.cm -3

No abstract