The genus Dendrobium Sw. is composed of 74 species and two varieties in China, and 32 species carry the name "Huangcao Shihu" on the herbal medicine market, making the identification of the origin of "Huangcao Shihu" difficult for consumers. Here, the ITS regions were sequenced and evaluated to differentiate the 18 Dendrobium species used as "Huangcao Shihu". Diversity in DNA sequences among various species was found with the inter-specific sequence divergence ranging from 3.2% to 37.9% in ITS1 and 5.0% to 26.6% in ITS2. Moreover, the variations within species were very low, ranging in sequence divergence from 0 to 3.0% in ITS1 and 0 to 4.0% in ITS2. Therefore, these species could be easily distinguished at the DNA level. Furthermore, based on the divergent ITS regions, five pairs of species-specific primers were designed and used for the rapid PCR identification of five Dendrobium species listed in the Chinese Pharmacopoeia.

Compared with the oxygen evolution reaction (OER), the urea oxidation reaction (UOR) is more likely to react in an alkaline electrolyte, and the thermodynamic voltage of urea electrolysis is 0.37 V, which is much smaller than the theoretical voltage of water-splitting (1.23 V). In this work, a Ni–Fe Prussian blue analogue is grown on MOF-Ni by two steps. First, carnation-shaped MOF-Ni is directly grown on the nickel foam. Second, nanocube-like Prussian blue analogue is grown on a MOF-Ni template. After phosphating reaction in a tube furnace, Ni2P/Fe2P (denoted as MNPBA-P) is obtained. MNPBA-P can still maintain the initial structure of nanocubes on a carnation-shaped MOF-Ni, which causes it to have better conductivity and larger electrochemical active surface area. As a bifunctional catalyst, MNPBA-P has a good performance in the catalytic reaction of cathode and anode. It is worth noting that when 0.5 M urea was added to the electrolyte, the high anode overpotential is greatly improved. Compared with overall water-splitting, MNPBA-P assembled into an electrolyzer requires smaller cell voltage in urea electrolysis. MNPBA-P || MNPBA-P electrolyzer only needs 1.50 V to afford 10 mA cm–2 in urea electrolyte and has a good stability for 12 h.

The urchin-like CoSx/Co-MOF as a bifunctional catalyst has good catalytic performance toward UOR and HER.

The rDNA ITS regions of five Dendrobium species were sequenced. Each Dendrobium species was found to have a unique sequence in the ITS region, so that they could be easily distinguished at the DNA level. The aligned 644 bp of the ITS region includes 235 bp ITS1, 163 bp 5.8S, and 246 bp ITS2. One hundred and eighty-nine sites are variable. The sequences of D. officinale could be easily distinguished from the other four adulterant species according to the sequence variation at 11 sites, 7 in ITS1, 1 in 5.8S, and 3 in ITS2. These could be used as molecular characters to distinguish the stems of D. officinale from the adulterants.