Nanostructured nickel phosphide-based catalysts having different sizes, phases, and morphology towards electrocatalytic, photocatalytic, and photoelectrocatalytic water splitting.

Nowadays the major research objective is to find an efficient renewable energy source which can be a potential solution to all our ongoing problems. With this regard, the interest has been blossoming toward effective photocatalytic HER and NRR at ambient condition. For the optimization of photocatalytic H2 evolution and NH3 production it is an exigent task to design a suitable photocatalytic semiconductor that hinders the low electron–hole separation efficiency. Benefiting from the combination of a 2D-2D semiconductor, we have proposed for the first time a series of p-MoS2/n-MgIn2S4 marigold flower-like heterojunction composites, with an excellent morphological contact interface through a facile two step hydrothermal process. The smart 2D-2D heterojunction structure provides large contact surface sites which reduce the migration distance between the separation sites of the photogenerated charge carrier to the heterojunction interface. This electron-rich system provided the multielectron pathway for the efficient reduction of nitrogen and can avoid the formation of high-energy intermediates. Thus, the high photocatalytic performance can be attributed to the heterojunction formation between two nanosheet, abundant exposed active sites via S–S linkage on the edge of metal sulfides and effective excitons separation. The developed MoS2/MIS heterojunction photocatalysts attain a high rate of NH3 production which is nearly 4 and 7 times higher than the bare MoS2 and MIS, and the rate of H2 evolution is 4 times higher than the bare MIS. The current investigation provides an excellent strategy to promote photocatalytic HER and NRR and sheds some light toward the development of efficient 2D based bifunctional materials.

Due to the enormous demand for effective conversion of solar energy and large-scale hydrogen production, cost-effective and long-lasting photocatalysts are believed to be necessary for global production of sustainable and clean hydrogen fuel. Robust and highly efficient p-n heterojunction photocatalysts have a striking ability to enhance light-harvesting capacity and retard the recombination of photoexcitons. A series of p-MoS/n-CaInS heterojunction composites with different MoS contents have been synthesized via a facile two-step hydrothermal technique in which rose-like p-MoS nanoflowers are decorated upon n-type cubic CIS microflowers. In the synthesis protocol highly dispersed MoS nanoflowers provided more active edge sites for the growth of c-CIS nuclei, leading to a hierarchical architecture with intimate interfacial contact. The formation of a hierarchical flower-like morphology of the photocatalyst has been established by an HRTEM and FESEM study. Electrochemical characterization, especially the slope of the curve from Mott-Schottky analysis and nature of the current from LSV, reveals the p-n heterojunction nature of the composite photocatalyst. The fabricated heterojunction photocatalysts were further examined for visible light photocatalytic H evolution. Far exceeding those for the neat c-CIS and MoS, it is seen that the p-MoS/n-CIS heterojunction photocatalyst with an optimum content of MoS exhibited enhanced H evolution using a 0.025 M NaS/NaSO solution as hole quenching agent under visible light illumination. The 0.5 wt % p-MoS/n-CIS photocatalyst presents a higher H production rate of 602.35 μmol h with 0.743 mA cm photocurrent density, 19 times and 8 times higher than those of neat c-CIS, respectively. This superior photocatalyic activity is due to the efficient separation of electron-hole charge carriers at the interface, as supported by a photoluminescence study and EIS measurements.

IntroductionIn connection to food insecurity, adaptation of new techniques or alteration of regular behavior is executed that translates to coping strategies. This paper has used data from food security and nutrition surveillance project (FSNSP), which collects information from a nationally representative sample in Bangladesh on coping behaviors associated with household food insecurity. To complement the current understanding of different coping strategies implemented by the Bangladeshi households, the objective of this paper has been set to examine the demographic and socio-economic characteristics of the food insecure households which define their propensity towards adaptation of different types of coping strategies.MethodologyFSNSP follows a repeated cross-sectional survey design. Information of 23,374 food insecure households available from February 2011 to November 2013 was selected for the analyses. Coping strategies were categorized as financial, food compromised and both. Multinomial logistic regression was employed to draw inference.ResultsMajority of the households were significantly more inclined to adopt both multiple financial and food compromisation coping strategies. Post-aman season, educational status of the household head and household women, occupation of the household’s main earner, household income, food insecurity status, asset, size and possession of agricultural land were found to be independently and significantly associated with adaptation of both financial and food compromisation coping strategies relative to only financial coping strategies. The relative risk ratio of adopting food compromisation coping relative to financial coping strategies when compared to mildly food insecure households, was 4.54 times higher for households with moderate food insecurity but 0.3 times lower when the households were severely food insecure. Whereas, households were 8.04 times and 4.98 times more likely to adopt both food compromisation and financial relative to only financial coping strategies if moderately and severely food insecure respectively when compared to being mildly food insecure.ConclusionHouseholds suffering from moderate and severe food insecurity, are more likely to adopt both financial and food compromisation coping strategies.

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