Hydrogen production using novel catalysts is regarded as one of the most needed technology for the future economic needs and water splitting to give H2 gas, which is a challenging task for large-scale production. This work reports the synthesis of Meso-Cu-BTC metal organic framework and further used for understanding its role in electrochemical hydrogen evolution reaction (HER) in 1 M NaOH solution. Meso-Cu-BTC electrocatalyst showed a less overpotential of 89.32 mV and an onset potential of 25 mV with an appreciable current density. Results show a low Tafel slope of 33.41 mVdec−1 and long-term durability. Thus, the overall results show that Meso-Cu-BTC acted as a good candidate for electrocatalysis towards hydrogen evolution.

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PurposeBased on the hypothesis of the environmental Kuznets curve (EKC), the purpose of this study is to investigate the relationship between environmental pollutants (as measured by CO2 emissions) and GDP for India, over the period 1980–2012. The presence of an inverted “U” shape relationship is examined while controlling for factors such as the degree of trade openness, foreign direct investment, oil prices, the legal system and industrialization.Design/methodology/approachTo verify whether the EKC follows a linear, quadratic or polynomial form, autoregressive distributed lag (ARDL) bounds testing approach for cointegration with structural breaks is adopted. The annual time series data for carbon emissions (CO2), economic growth (GDP), industrial development (industrialization), foreign direct investment and trade openness have been obtained from World Development Indicators online database. Crude oil price (international price index) for the period is collected from the International Monetary Fund. Data for total petroleum consumption are collected from the US Energy Information Agency. Data for economic freedom variables are from the Fraser Institute's Economic Freedom Index's online database.FindingsThe findings support the existence of inverted U-shaped EKC in the short-run, but not in the long-run. A linear monotonic relationship has also been estimated in select model specifications. Additionally, trade openness has been estimated to reduce emissions in models, which incorporate FDI. Else, where significant, its impact on carbon emissions is adverse. A rise in fuel price leads to reduction in carbon emissions across model specifications. Further, the lower size of government degrades the environment both in the long-run and short-run.Practical implicationsGiven the existence of the pollution haven hypothesis, wherein more trade and foreign direct investments cause environmental degradation, the paper proposes formulation of appropriate regulatory mechanisms that are environmentally friendly. Additionally, India's new economic policies, favoring liberalization, privatization and globalization, reinforces the need to strengthen environmental regulations.Originality/valueIncorporation of economic freedom as measured by the “Size of Government” in the EKC model is unique. “Size of Government” deserves a special mention. The rationale for including this explanatory variable is to understand whether countries with lower government size are more polluting. After all, theory does suggest that goods and services, which have higher social cost vis-à-vis private cost, shall be overproduced in economies that adopt more market-friendly policies, necessitating government intervention. In the study, size of government is measured as per the definition and methodology adopted by Fraser Institute's Economic Freedom of the World Index.

A self-powered water electrolyzer system was constructed via integration of a solar cell with the fabricated CMS/Ni electrolyzer (acts as both anode (OER) and cathode (HER), which demonstrated potential application towards next-generation energy conversion and management systems.

A wide variety of electrocatalysts has been evolved for hydrogen evolution reaction (HER) and it is reasonable to carry out HER with low cost electrocatalyst and a good efficiency. In this study, Cu3N was synthesized by nitridation of Cu2O and further utilized as an electrocatalyst towards HER. The developed Cu3N electrocatalyst was tested and results showed a low overpotential and moderate Tafel slope value (overpotential: 149.18 mV and Tafel slope 63.28 mV/dec at 10 mA/cm2) in alkaline medium with a charge transfer resistance value as calculated from electrochemical impendence spectroscopy being 1.44 Ω. Further from the experimental results, it was observed that the reaction kinetics was governed by Volmer–Heyrovsky mechanism. Moreover, Cu3N has shown an improved rate of electron transfer and enhanced accessible active sites, due to its structural properties and electrical conductivity. Thus the overall results show an excellent electrochemical performance, leading to a new pathway for the synthesis of low cost electrocatalyst for energy conversion and storage.

The development of high-performance bifunctional palladium-based (Pd) alloys for the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) is a great challenge in direct methanol fuel cells. The incorporation of an oxophilic atom into the Pd atom is an effective strategy to enhance the electrocatalytic activity of the catalysts. Herein a sphere-like PdNi alloy (sPdNiA) was developed via a simple hydrazineassisted reduction method to overcome the kinetic drawbacks of palladium and delivers superior ORR/MOR performance. The successful alloy formation, the induced strain effect in the electronic structure, and structural characteristics of the sPdNiA were confirmed through XRD, XPS, and HR-TEM studies. As a result, for ORR, the sPdNiA exhibits a positive halfwave potential (E 1/2 ) of ∼0.854 V (vs RHE) compared to the pure Pd (0.833 V vs RHE) nanoparticles. For MOR, the sPdNiA presents the low onset potential and high mass activity of 518 mA mg Pd −1 in 1.0 M KOH electrolyte. Furthermore, the temperature-dependent MOR and 3D Bode plot investigations reveal a five-fold higher mass activity at elevated temperature (60 °C) with a lower activation energy (E a ). For the first time, the direct methanol fuel cell is fabricated utilizing sPdNiA as a bifunctional electrode, exhibited a higher peak power density (P max ) of 34 mW cm −2 , whereas 22 mW cm −2 was obtained for Pd Np-based fuel cells. Incorporating oxophilic atom (Ni) not only improves the performance of Pd but significantly reduces the cost of the catalyst material by lowering the Pd content.

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