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Cellulose, hemicellulose, and lignin are three kinds of biopolymer in lignocellulosic biomass, and the utilization of the three biopolymers to synthesize hydrogel adsorbent could protect the environment and enhance the economic value of the biomass. A novel hydrogel adsorbent was prepared using cellulose, lignin, and hemicellulose of wheat straw by a one-pot method, and the adsorbent showed excellent adsorption performance for copper(II) ions. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis showed that the prepared straw-biopolymer-based hydrogel had porous structure, and cellulose fibrils had crosslinked with lignin and hemicellulose by poly(acrylic acid) chains. The effects of contact time, initial concentration, and temperature on the copper(II) ion removal using the prepared hydrogels were investigated, and the obtained results indicated that the adsorption kinetics conformed to the pseudo-second-order and Elovich equation models and the adsorption isotherm was in accord with the Freundlich model. The adsorption thermodynamics study indicated that the adsorption process was spontaneous and accompanied by heat. X-ray photoelectron spectroscopy analysis revealed that the adsorption behavior resulted from ion exchange. The prepared hydrogel based on cellulose, hemicellulose, and lignin could be used for water treatment and soil remediation because of its high performances of excellent heavy metal ion removal and water retention.

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The garnet-type metal oxide Li7La3Zr2O12(LLZO) is considered to be one of the most promising compounds for solid lithium ion batteries because of its high ionic conductivity at room temperature and excellent chemical stability with the metal Li. LLZO is unstable in humid air and easily forms Li2CO3 on the surface, which leads to the decrease of ion conductivity. In this paper, chemical treatment by oxalic acid is carried out to remove the lithium carbonate on the surface of LLZO. The results show that oxalic acid with a concentration ratio of 5% can completely remove lithium carbonate. Composite polymer electrolyte membranes fabricated by the polyvinylidene fluoride (PVDF)and LLZO before and after the acid treatment are prepared to evaluate the effect on ionic conductivity. The ionic conductivity is 1.4×10−4 Scm−1 and 9.0×10−4 S cm−1 for samples added the LLZO before and after the acid treatment, respectively.

Rareearthupconversionfluorescentnanomaterialshavedrawngreatattentionasnovelfluorescent probesbecauseoftheirmanyuniquemerits,suchassuperiorphotostability,narrowemissionspectra,longlifetime andlargerStokesshift.Byusingnearinfraredlaserasexcitationlightsource,itisfeasiblefortheupconversion fluorescentnanomaterialsasexcellentfluorescentprobesfor invivo fluorescenceimagingduetothehighlight penetrationdepthinbiologicaltissues,absenceofphotodamagetoliveorganisms,lowautofluorescence background.Recentprogressofpreparationandbiologicalapplicationofrareearthupconversionfluorescent nanomaterialsisreviewedinthispaper.