Currently, global climate change and oil pollution are two main environmental concerns for sea cucumber (Apostichopus japonicus) aquaculture. However, no study has been conducted on the combined effects of elevated temperature and oil pollution on sea cucumber. Therefore, in the present study, we treated sea cucumber with elevated temperature (26 °C) alone, water-accommodated fractions (WAF) of Oman crude oil at an optimal temperature of 16 °C, and Oman crude oil WAF at an elevated temperature of 26 °C for 24 h. Results showed that reactive oxygen species (ROS) level and total antioxidant capacity in WAF at 26 °C treatment were higher than that in WAF at 16 °C treatment, as evidenced by 6.03- and 1.31-fold-higher values, respectively. Oxidative damage assessments manifested that WAF at 26 °C treatment caused much severer oxidative damage of the biomacromolecules (including DNA, proteins, and lipids) than 26 °C or WAF at 16 °C treatments did. Moreover, compared to 26 °C or WAF at 16 °C treatments, WAF at 26 °C treatment induced a significant increase in cellular apoptosis by detecting the caspase-3 activity. Our results revealed that co-exposure to elevated temperature and crude oil could simulate higher ROS levels and subsequently cause much severer oxidative damage and cellular apoptosis than crude oil alone on sea cucumber.

The search for new heterometallic metal pseudohalides will be significant for the development of novel functional materials. In this work, a new silver/cadmium heterometallic thiocyanate templated by benzyl viologen has been synthesized and structurally determined, i.e., {(BV)[Ag₂Cd(SCN)₆]}_n (BV²⁺ = benzyl viologen). The interesting 1-D double chain [Ag₂Cd(SCN)₆]_n²ⁿ⁻ was constructed from the CdN₆ octahedron and Ag₂SCN₆ dimers via μ₂-SCN and μ₃-S,S N SCN bridge, in which the Ag···Ag interaction can be found. Inter-molecular C-H···S/N hydrogen bonds between BV²⁺ cations and [Ag₂Cd(SCN)₆]_n²ⁿ⁻ chains contribute to the formation of a stable 3-D network. The short S···N distance implies the strong charge transfer (CT) interactions between the electron-rich silver/cadmium thiocyanate donor and BV²⁺ acceptor. This hybrid can exhibit a photo-generated current performance with an intensity of 1.75 × 10⁻⁸ A. Interestingly, this hybrid can present good photocatalytic degradation performance on rhodamine B in artificial seawater with a degradation ratio of 86.5% in 240 min. This work provides a new catalyst way for the organic dye-type ocean pollutant treatments.

Photocatalytic degradation is a leading technology for complete mineralization of organic dyes in the ocean. In this work, a new viologen-bearing silver-thiocyanate-based photocatalyst, i.e., {(i-PrV)[Ag₂(SCN)₄]}_n (i-PrV²⁺ = isopropyl viologen) has been synthesized and structurally determined, with results showing that it can exhibit excellent degradation performance on rhodamine B (RhB) in artificial seawater. The planar i-PrV²⁺ dications are confined in the free voids of the [Ag₂(SCN)₄]_n²ⁿ⁻ layer with a two-dimensional (6,3) mesh, and strong C-H···S hydrogen bonds contribute to its structural stabilization. This photocatalyst was further characterized by powder X-ray diffraction (PXRD), UV-Vis, fluorescence, and photo/electrical responsive measurements, pointing to its application in visible-light-driven catalysis. Interestingly, using this photocatalyst, good photocatalytic degradation performance on rhodamine B in artificial seawater could be observed. The dye pollutant could be degraded with a high degradation ratio of 87.82% in 220 min. This work provides a promising catalyst for organic dye-type ocean pollutant treatments.