Solar water splitting provides a promising path for sustainable hydrogen production and solar energy storage. In recent times, metal−organic frameworks (MOFs) have received considerable attention as promising materials for diverse solar energy conversion applications. However, their photocatalytic performance is poor and rarely explored due to rapid electron− hole recombination. Herein, we have developed a material MOF@rGO that exhibits highly enhanced visible-light photocatalytic activity. A real-time investigation reveals that a strong π−π interaction between MOF and rGO is responsible for efficient separation of electron−hole pairs, and thereby enhances the photocatalytic hydrogen production activity. Surprisingly, MOF@rGO showed ∼9.1-fold enhanced photocatalytic hydrogen production activity compared to that of pristine MOF. In addition, it is worth mentioning here that remarkable apparent quantum efficiency (0.66%) is achieved by π−π interaction mediated charge carrier separation.

Conductive inks are a recent progress in electronics and have a promising future applications in flexible electronics and smart applications. In this review we tried to focus on a particular conductive ink, based on copper nanoparticles. Although wide research is being done all over the world, few complications are yet to be solved with perfection. We tried to focus on some of the complications involved in the synthesis and their various applications in the different fields of science. Conductive inks have promising applications in the present trend of science and technology. The main intention behind this review is to list out some of the best methods to synthesize copper nanoparticles according the category of synthesizing them. We chose copper nanoparticles synthesis and preparation of conductive inks because copper is a very abundant material possessing high conductivity (after silver), it has huge potential to replace expensive conductive inks made of silver, graphene, CNTs etc. The reason behind insisting on copper is also due to its properties such as ductility, malleability, thermal dissipation agent, possess anti microbial nature etc. In this review, we have listed out some of the best methods of synthesizing copper conductive ink and their usage in various printing techniques. Different methods of sintering for obtained conductive patterns are also included.

The photoelectrochemical (PEC) approach is attractive as a promising route for the nitrogen reduction reaction (NRR) toward ammonia (NH3) synthesis. However, the challenges in synergistic management of optical, electrical, and catalytic properties have limited the efficiency of PEC NRR devices. Herein, to enhance light‐harvesting, carrier separation/transport, and the catalytic reactions, a concept of decoupling light‐harvesting and electrocatalysis by employing a cascade n+np+‐Si photocathode is implemented. Such a decoupling design not only abolishes the parasitic light blocking but also concurrently improves the optical and electrical properties of the n+np+‐Si photocathode without compromising the efficiency. Experimental and density functional theory studies reveal that the porous architecture and N‐vacancies promote N2 adsorption of the Au/porous carbon nitride (PCN) catalyst. Impressively, an n+np+‐Si photocathode integrating the Au/PCN catalyst exhibits an outstanding PEC NRR performance with maximum Faradaic efficiency (FE) of 61.8% and NH3 production yield of 13.8 µg h–1 cm–2 at −0.10 V versus reversible hydrogen electrode (RHE), which is the highest FE at low applied potential ever reported for the PEC NRR.