The invention of paper as a writing material greatly promoted the development and spread of civilization. However, its large-scale production and utilization has also brought about huge environmental and sustainability concerns. It is desirable to develop a strategy for paper that can be used in a reprintable manner. In this work, ZnO-based photocatalytic reactions have been applied in preparing a reprintable paper that works through the color conversion of methylene blue. The resulting paper does not require additional ink and can be repeatedly printed for 20 cycles keeping over 77% of the initial contrast ratio. The reprintable raw materials can be retained for more than 2 months in the ambient environment. A fast color-switching time of about 10 s has been achieved, which can be attributed to the high photo-induced electron transfer rate from the ZnO to the dyes.

中文翻译：

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利用基于ZnO的光催化染料颜色转换实现可重印纸

纸张作为书写材料的发明极大地促进了文明的发展和传播。但是，其大规模生产和利用也带来了巨大的环境和可持续性问题。期望开发一种可以以可重印方式使用的纸张策略。在这项工作中，基于ZnO的光催化反应已用于制备可重印纸，该纸通过亚甲基蓝的颜色转换而起作用。所得纸张不需要额外的墨水，可以重复打印20个循环，保持初始对比度的77％以上。可重印的原材料可以在周围环境中保留2个月以上。已经实现了大约10 s的快速颜色切换时间，