Search

Resource partitioning through temporal, spatial and/or trophic dimensions is suggested as a mechanism for long‐term coexistence among sympatric species. However, how the combined effects of the different dimensions contribute to the partitioning during the ontogenetic process is unclear.We sampled two sympatric icefish species [Protosalanx hyalocranius (Abbott, 1901) and Neosalanx taihuensis (Chen, 1956)] monthly from July 2015 to June 2016 in Hongze Lake, China. We evaluated the hypothesis that combined effects of separation in gonad development dynamics and ontogenetic diet shifts facilitate resource partitioning in temporal and trophic dimensions during the entire life cycle process of the two icefish species.Increased gonadosomatic index (GSI) of female P. hyalocranius occurred during October 2015 to January 2016, and that of female N. taihuensis occurred during January to March 2016. Thus, energy and nutrition investments in gonad development separated seasonally between the two species. Consequently, temporal separations in gonad development between P. hyalocranius (GSI peaked in January) and N. taihuensis (GSI peaked in March) indicated potential segregations in spawning time and consequent larval abundance peaks, suggesting reduced overlap of prey consumption during the early life stages.The dominant diet of P. hyalocranius shifted from cladocerans to copepods, and then shrimp, and finally to fish during its ontogeny, whereas the dominant diet of N. taihuensis changed gradually from cladocerans to copepods during its ontogeny. The diet overlap in cladocerans during May was high between the two species.Our findings support the hypothesis of an associative strategy, combining temporal (separations in gonad development and subsequently spawning time) and trophic (ontogenetic diet shifts) dimensions, for the resource partitioning between P. hyalocranius and N. taihuensis, which may be an important mechanism for long‐term coexistence among sympatric short‐lived fishes. [ABSTRACT FROM AUTHOR]

The development of high activity, low-cost and stability hydrogen evolution reaction (HER) catalysts is a core issue in the field of water splitting. Herein, the bimetallic CoMo MOFs-derived N-doped carbon nanospheres with Co/Mo–N bonds is proposed to effectively improve the electrocatalytic HER performance. Meanwhile, the combination of the porous and spherical structure further promotes the effective contact on the electrode/electrolyte interface while enhancing the electrolyte into the inner structure of the material for a fast HER process. In addition, the N-doped and bimetallic Co/Mo oxides on the rough surface of nanospheres have the capability to furnish more electrocatalytic active sites. The obtained electrocatalyst owns the small overpotential of 112 mV at 10 mA cm−2 and Tafel slope of 106.8 mV dec−1 in 1.0 M KOH solution. This work provides a new prospect for the rational design and fabrication of bimetallic active sites in carbon nanomaterials electrocatalysts in the relevant energy applications. [Display omitted] • Bimetallic CoMo MOFs-derived N-doped carbon nanospheres is proposed to effectively improve the electrocatalytic HER performance. • The formation of Co–N and Mo–N, which would provide a fast electron transfer path in electrocatalytic process. • The formation of CoO and CoMoO 3 species could synergistic promote the adsorption and reaction of the H ads intermediates. [ABSTRACT FROM AUTHOR]

Fabrication of highly efficient and earth-abundant bifunctional electrocatalyst to accelerate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for overall water splitting. In this work, bimetallic Co/Mo oxides modified reduced graphene oxide (rGO) was synthesized using a simple one-pot hydrothermal method, which significantly improved the electrocatalytic activity in both HER and OER. Under the optimal conditions, the double layer capacitance of rGO modified by Co/Mo bimetal is 78.08 mF cm−2. The overpotential required for HER to reach -10 mA cm−2 current density is 488 mV, the dynamic Tafel slope is 126 mV dec−1. The overpotential required for OER to reach 10 mA cm−2 current density is 420 mV, the slope of kinetic Tafel is 169 mV dec−1. This work provides a new prospect for the rational design and fabrication of efficient HER/OER bifunctional electrocatalysts in electrochemical energy device application.Graphical Abstract: Fabrication of highly efficient and earth-abundant bifunctional electrocatalyst to accelerate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for overall water splitting. In this work, bimetallic Co/Mo oxides modified reduced graphene oxide (rGO) was synthesized using a simple one-pot hydrothermal method, which significantly improved the electrocatalytic activity in both HER and OER. Under the optimal conditions, the double layer capacitance of rGO modified by Co/Mo bimetal is 78.08 mF cm−2. The overpotential required for HER to reach -10 mA cm−2 current density is 488 mV, the dynamic Tafel slope is 126 mV dec−1. The overpotential required for OER to reach 10 mA cm−2 current density is 420 mV, the slope of kinetic Tafel is 169 mV dec−1. This work provides a new prospect for the rational design and fabrication of efficient HER/OER bifunctional electrocatalysts in electrochemical energy device application. [ABSTRACT FROM AUTHOR]