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Thorium as a potential nuclear fuel for the next-generation thorium-based molten salt reactors holds significant environmental and economic promise over the current uranium-based nuclear reactors. However, because thorium (Th4+) usually coexists with other rare earth elements, alkali or alkaline earth metals in minerals, or highly acidic radioactive waste, seeking acid-resistant sorbents with excellent selectivity, high capacity, and fast removal rate for Th4+ is still a challenging task. In this work, we investigated a robust layered metal sulfide (KInSn2S6, KMS-5) for Th4+ removal from strong acidic solutions. We report that KMS-5 could capture Th4+ from a 0.1 M HNO3 solution with extremely high efficiency (∼99.9%), fast sorption kinetics (equilibrium time < 10 min), and large distribution coefficient (up to 1.5 × 106 mL/g). Furthermore, KMS-5 exhibited excellent sorption selectivity towards Th4+ in the presence of large amounts of competitive metal ions like Eu3+, Na+, and Ca2+. This extraordinary capture property for Th4+ is attributed to the facile ion exchange of Th4+ with K+ in the interlayers and subsequent formation of a stable coordination complex via Th-S bonds. These results indicate that KMS-5 is a promising functional sorbent for the effective capture of Th4+ from highly acidic solutions.

Tin dioxide (SnO2) as an efficient electron transport layer (ETL) has been demonstrated for emerging high-performance organic-inorganic hybrid perovskite solar cells (PSCs). However, the low-temperature solution-processed SnO2 usually results in high trap-state density and current-voltage hysteresis. Here, we reported an effective strategy to solve this problem by incorporating graphene ink into the low-temperature processed SnO2 for planar structure PSCs. The electron extraction efficiency has been significantly improved with graphene-doped SnO2 ETL coupled with attenuated charge recombination at the ETL/perovskite interface. The power conversion efficiency (PCE) of PSCs based on the graphene-SnO2 ETL reached over 18% with negligible hysteresis. Incorporation of graphene into the ETL layer also enhanced the device stability retaining 90% of the initial PCE value after storing in ambient condition with a relative humidity of 40 ± 5% for 300 h. Our results provide an important insight into further efficiency boost in SnO2-based low-temperature processed PSCs.

Electron-selective layers (ESLs) and hole-selective layers (HSLs) are critical in high-efficiency organic-inorganic lead halide perovskite (PS) solar cells for charge-carrier transport, separation, and collection. We developed a procedure to assess the quality of the ESL/PS junction by measuring potential distribution on the cross section of SnO

A perovskite solar cell with a thin TiO2 compact film prepared by thermal oxidation of sputtered Ti film achieved a high efficiency of 15.07%. The thin TiO2 film prepared by thermal oxidation is very dense and inhibits the recombination process at the interface. The optimum thickness of the TiO2 compact film prepared by thermal oxidation is thinner than that prepared by spin-coating method. Also, the TiO2 compact film and the TiO2 porous film can be sintered at the same time. This one-step sintering process leads to a lower dark current density, a lower series resistance, and a higher recombination resistance than those of two-step sintering. Therefore, the perovskite solar cell with the TiO2 compact film prepared by thermal oxidation has a higher short-circuit current density and a higher fill factor.

Efficient organic solar cells (OSCs) based on regioregular of poly (3-hexylthiophene):fullerene derivative [6,6]-phenyl-C61butyric acid methyl ester composites have been fabricated on indium tin oxide (ITO) coated glass substrates by using a sputtered sulfur-doped molybdenum oxide (S-MoO3) film as anode interface layer (AIL). With the help of X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy, we find that oxygen flow ratio control can modulate the amount of sulfur doping into MoO3, then further tune the Mo(+4)/Mo(+5)/Mo(+6) composition ratios, Fermi level, electron affinity, valence band ionization energy and band gap of MoO3. A partially occupied Mo 4d-bands of Mo(5+) and Mo(4+) states modulated by sulfur doping are the main factor which influences the valence electronic structure of S-MoO3.These orbitals overlap interrelation push the valence band close to S-MoO3's Fermi level, thus make it into a p-type semiconductor. S-MoO3 with smaller ionization energy and electron affinity is better suitable as an efficient AIL. On the basis of these AILs, a photovoltaic power conversion efficiency up to 3.69% has been achieved, which is 12% higher than that in pure MoO3 AIL case. The result thus shows that sulfur doping is a useful method to modify anode interface layer for improving the hole-transport properties of MoO3, which can improve the device performances.