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We show that the cooperation of lead thiocyanate additive and a solvent annealing process can effectively increase the grain size of mixedcation lead mixed-halide perovskite thin films while avoiding excess lead iodide formation. As a result, the average grain size of the wide-bandgap mixed-cation lead perovskite thin films increases from 66 ± 24 to 1036 ± 111 nm, and the mean carrier lifetime shows a more than 3-fold increase, from 330 ns to over 1000 ns. Consequently, the average open-circuit voltage of wide-bandgap perovskite solar cells increases by 80 (70) mV, and the average power conversion efficiency (PCE) increases from 13.44 ± 0.48 (11.75 ± 0.34) to 17.68 ± 0.36 (15.58 ± 0.55)% when measured under reverse (forward) voltage scans. The best-performing wide-bandgap perovskite solar cell, with a bandgap of 1.75 eV, achieves a stabilized PCE of 17.18%.

Tin oxide (SnO 2 ) electron selective layers (ESLs) processed by low-temperature plasma-enhanced atomic layer deposition (PEALD) hold promise for fabricating lightweight and efficient flexible lead halide perovskite solar cells (PVSCs). However, the as-synthesized SnO 2 ESLs typically lead to flexible PVSCs with lower open-circuit voltage (V OC ) and fill factor (FF) as well as a higher degree of current density−voltage (J−V) hysteresis, compared to PVSCs fabricated on rigid substrates. Here, we report that facile water vapor treatment of PEALD-synthesized SnO 2 ESLs can effectively improve the V OC and FF while reducing the degree of J−V hysteresis. The improvement in device performance is mainly attributed to the improved conductivity and electrical mobility of SnO 2 ESLs enabled by water vapor treatment. With such treatment, our best flexible PVSC fabricated on a commercial substrate shows a power conversion efficiency of 18.36 (17.12)% when measured under a reverse (forward) voltage scan and a stabilized efficiency of 17.08%, which is the highest reported efficiency for flexible PVSCs with the regular structure.

Practical application of electrochemical water splitting demands durable, efficient, and non-noble metal catalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we report a new hydrogen evolution nanowire electrocatalyst, consisting of S-doped CoWP nanoparticles embedded in S-and N-doped carbon matrix (S-CoWP@(S,N)-C), which is in situ transformed from Hofmanntype (Co, W)-based metal−organic framework (MOF) nanowires. Because of S and N doping to the carbon matrix and the S doping to CoWP nanoparticles, the obtained S-CoWP@(S,N)-C catalyst reaches a current density of −10 mA cm −2 at −35 and −67 mV (vs RHE) in acidic and alkaline electrolytes, respectively. Powered by a lead halide perovskite solar cell, an unassisted two-electrode solar water-splitting device using MOF-derived S-CoWP@(S,N)-C HER electrocatalysts and S-CoW@(S,N)-C OER electrocatalysts displays a solar-to-hydrogen conversion efficiency of 10.98%. Our method is highly applicable for developing robust electrocatalysts toward efficient and low-cost solar-driven water splitting.

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Hydrogen therapy, as a star therapeutic modality, has recently acquired much attention in the field of anticancer medicine. Evidence suggests that hydrogen can selectively reduce intratumoral overexpressed hydroxyl radicals (•OH) to break the redox homoeostasis and thereby result in redox stress and cell damage. As a reactive oxygen species‐related noninvasive modality, photodynamic therapy (PDT) has been approved for varied tumor treatments clinically. For implementing tumor therapy with enhanced anticancer efficacy and attenuated side effects, here a biocompatible palladium nanocrystals‐integrated nanoscale porphyrinic metal–organic framework (NPMOF) is designed to develop a novel combined therapy modality, that is, synergistic hydrogen/photodynamic therapy. The NPMOF is employed simultaneously as the photosensitizer for PDT and as the nanocarrier to support palladium nanocrystals, which is further used as the hydrogen vehicle. The final hydrogen‐containing nanosystems exhibit a persistent reductive hydrogen release behavior and considerable light‐activated singlet oxygen (1O2) generation without mutual interference, contributing to the adequate disturbance of tumor microenvironment redox steady‐state for synergistically inducing tumor cell death. Ultimately, by coupling of tumor‐selective hydrogen therapy and PDT, the designed nanosystems realize the augmented therapeutic outcome with minimal side effects, providing a safe and efficient tumor treatment for future clinical translation.

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