作者感谢中国国家自然科学基金 （82001945）、上海浦江计划 （20PJ1410700） 和上海科技大学的启动资助。作者感谢上海科技大学物理科学与技术学院高分辨率电子显微镜中心 （ChEM） （No.EM02161943） 获取材料特性描述支持。作者感谢上海科技大学物理科学与技术学院分析仪器中心 （#SPST-AIC10112914） 提供的光谱测试支持和 XRD 测试支持。作者还感谢李剑峰教授在材料表征方面的帮助。

1. Zn2GeO4 的合成：Mn PLNPs
<ol><li>将 10 mM 氢氧化钠溶解在 5 mL 去离子水中，制备 2 M/L 氢氧化钠溶液。</li>
	<li>将 2 mM 氧化锗加入 5 mL 氢氧化钠溶液中，制备 0.4 M/L 锗酸钠溶液，然后在室温下搅拌约 30 分钟。</li>
	<li>将 4 mM 氯化锌、0.01 mM 硝酸锰和 600 μL 硝酸（65%-68%，wt）加入装有 22 mL 去离子水的 100 mL 小烧杯中。 注意： 硝酸的添加应严格在通风橱中进行，并确保周围没有明火或加热。</li>
	<li>剧烈搅拌，直到步骤 1.3 的溶液完全溶解。</li>
	<li>将 2 mM 锗酸钠溶液缓慢加入到步骤 1.4 的溶液中。向溶液中加入 1 mL 聚乙二醇 （PEG;300， Mw）。</li>
	<li>将校准过的 pH 计探头放入溶液中，监测反应系统的 pH 值。设置相对轻柔的搅拌，以避免溶液飞溅以及搅拌棒与探针之间的碰撞。</li>
	<li>将质量分数为 25%-28% 的氢氧化铵逐滴加入溶液中，并根据要研究的发光性质将溶液的 pH 值调节至 6.0、8.0 或 9.4。请务必缓慢加入氢氧化铵，并时刻监测溶液的 pH 值变化，以防止体系过酸或过碱，以免影响纳米材料的形貌和发光性能。</li>
	<li>用密封膜盖住烧杯，并在室温下搅拌溶液 1 小时。尽量不要将系统暴露在空气中，以防止灰尘进入并引起溶剂挥发，同时以恒定速度搅拌，以免在系统充分混合时系统的液位飞溅。</li>
	<li>将溶液转移到特氟龙衬里的高压灭菌器中，并将其置于 220 °C 的电动恒温干燥箱中 4 小时。 注意：应根据系统的体积选择合适的特氟龙内衬高压釜，并保持反应器清洁。添加的原材料的体积不应超过高压釜体积的 1 /3。同时，在将高压灭菌器放入电恒温干燥箱之前，请确保高压灭菌器完全关闭。</li>
	<li>反应完成后关闭电恒温干燥箱，等待系统冷却至室温后取出反应器。请务必等到反应器完全冷却且压力降低到安全范围后再进行下一步，以避免高温与皮肤直接接触。</li>
	<li>缓慢打开反应器，将反应溶液转移至两个 50 mL 离心管中。用 40 mL 乙醇冲洗反应器，然后将乙醇溶液转移到相同的离心管中。</li>
	<li>涡旋 30 秒，使溶液均匀混合，然后在室温下以 4000 x g 离心样品 15 分钟并去除上清液。</li>
	<li>向每个离心管中加入 10 mL 去离子水，并超声处理 5 分钟（240 W，40 kHz）以重新分散产物。</li>
	<li>向每个离心管中加入 20 mL 乙醇并涡旋 30 秒以均匀混合溶液。</li>
	<li>在室温下继续根据前面提到的设置（4000 x g ，15 分钟）离心产品，并弃去上清液。</li>
	<li>超声处理 5 分钟，将产物分散在 2 mL 甲醇溶液中，用密封膜密封样品并将其储存在 4 °C 冰箱中，以防止样品污染和溶剂蒸发，以备将来的照明应用。</li>
</ol>2. ZnGa2O4 的合成：Cr PLNPs
<ol><li>将 12 mM Ga（NO3）3.xH 2O、7.2 mM ZnCl2 和 0.024 mM Cr（NO3）3.9H 2O 溶解在 30 mL 去离子水中。</li>
	<li>向溶液中加入 1 mL PEG （300， Mw）。向溶液中加入氢氧化铵 （25%-28% wt），轻轻搅拌至达到 9.0-9.4 的 pH 值。请务必控制搅拌速度，以便溶液可以充分混合而不会溅到 pH 计上。</li>
	<li>用密封膜盖住烧杯，并在室温下搅拌溶液 1 小时。尽量减少系统与空气的接触，以防止灰尘进入和溶剂蒸发。同时，控制搅拌速度，使系统在充分混合时不会飞溅。</li>
	<li>将溶液转移到特氟龙衬里的高压灭菌器中，并在 220 °C 下运行 6 小时。温度降至室温后取出容杯。在进行后续操作之前，请确保反应容器已完全冷却，并且压力已降至安全范围，并避免高温与皮肤直接接触。</li>
	<li>将反应溶液转移至两个 50 mL 离心管中。用 40 mL 乙醇冲洗反应器，然后将乙醇溶液转移到相同的离心管中。</li>
	<li>涡旋 30 秒以混合溶液，然后在室温下以 4000 x g 离心样品 15 分钟并去除上清液。</li>
	<li>向每个离心管中加入 10 mL 去离子水，并超声处理 5 分钟以重新分散产物。</li>
	<li>向每个离心管中加入 20 mL 乙醇并涡旋 30 秒以均匀混合溶液。如前所述，在室温下继续离心产品（4000 x g，15 分钟）并弃去上清液。</li>
	<li>超声处理 5 分钟，将产物分散在 2 mL 去离子水中，并用密封膜密封样品进行储存。</li>
</ol>3. 原料提纯
<ol><li>如下所述，通过柱色谱法纯化甲基丙烯酸甲酯 （MMA）。<ol><li>用碱性氧化铝（100-200 目）填充色谱柱的一半，并用玻璃棒轻轻压实。用氧化铝填充色谱柱时，注意填料的分布均匀和均匀压实，以提高分离效率。</li>
		<li>加入少量 MMA 并打开下面的 PTFE 节气门活塞。一旦溶剂层润湿了整个氧化铝并且液体流出，添加更多的 MMA 并多次重复此过程。整个 MMA 添加到碱性氧化铝中的质量比为：1：50 的时间代表过程结束。</li>
		<li>将最终收集的MMA样品放入玻璃瓶中，用密封膜密封并储存在4°C。 注意：由于 MMA 的挥发性很强，整个过程应在通风橱中进行。同时，操作人员应佩戴口罩和穿实验室外套。</li>
	</ol></li>
	<li>如下所述，通过重结晶纯化偶氮二异丁腈 （AIBN）。<ol><li>制备 50 mL 乙醇和蒸馏水体积比为 7：3 的混合溶液，并加热溶液。</li>
		<li>当溶液沸腾时加入 5 g AIBN 并搅拌以均匀混合溶液。</li>
		<li>如下所述，通过热过滤去除不溶性杂质。<ol><li>将滤纸紧贴三角漏斗的内壁，并确保滤纸低于漏斗边缘。</li>
			<li>将玻璃棒靠在滤纸的三层部分上。如果玻璃棒没有靠在滤纸的三层截面上，它可能会刺穿滤纸，导致过滤效率低下。</li>
			<li>将装有溶液的烧杯尖端靠近玻璃棒，趁热倒入。此步骤的目的是防止液体液滴飞溅。</li>
			<li>用 10 mL 冷蒸馏水冲洗烧杯，再次进行上述过滤过程;重复 3 次。</li>
		</ol></li>
		<li>由于冷却过程中溶解度降低，溶液变得过饱和，导致晶体沉淀。将收集的溶液放入 4 °C 的冰箱中冷却和结晶。样品将以白色针状晶体的状态出现。</li>
		<li>用铝箔密封样品并储存在 4 °C。 注意 由于 AIBN 的毒性，手术过程中应采取保护措施，同时避免与明火、高温和氧化剂接触。</li>
	</ol></li>
</ol>4. 甲基丙烯酸甲酯 （MMA） 的共聚反应
<ol><li>将水浴温度设置为 80 °C。 注意：水的温度对聚合速率有严重影响，从而影响最终产品的形成。因此，应严格保证水浴的温度不要太高。</li>
	<li>称取 20 g MMA 放入 100 mL 茄子形瓶中。实验前保持容器干燥。 注意：选择茄子形瓶子是为了便于水浴加热和用系统中的氮气代替空气。尝试在通风良好的环境中称量样品，同时佩戴口罩。</li>
	<li>将预先准备好的 Zn2GeO4：Mn 甲醇溶液加入反应容器中。</li>
	<li>在室温下，借助超声波将样品彻底溶解在 MMA 中约 10 分钟（240 W，40 kHz）。保持反应容器密封，以防止溶剂蒸发，并避免在超声处理过程中温度过高。</li>
	<li>向溶液中加入 0.012 g AIBN 并完全混合溶液。 注意：AIBN 应在无水条件下使用，并确保实验操作周围没有明火。请务必佩戴防护装备。</li>
	<li>将烧瓶置于 80 °C 水浴中，用 N2 吹扫反应系统中的空气约 35 分钟。当反应即将结束时，轻轻摇晃反应容器。如果溶液没有剧烈摇晃，则证明反应成功。 注意：反应时间会随水浴的温度而变化。确保水浴的温度达到 80 °C 并开始计时 35 分钟。</li>
	<li>反应结束后，迅速将反应容器转移到冰浴中，使其快速冷却。 注：此过程应尽可能快，以避免 MMA 的过度预聚，并且可以在反应间隔期间提前制备冰浴。</li>
	<li>将溶液缓缓倒入二维或三维模具中，将模具放入40°C电恒温烘箱中10 h，70°C放置8 h，再100°C放置2 h，得到目标材料。</li>
	<li>反应停止后关闭电恒温干燥箱，使其冷却至室温。反应系统充分冷却后，打开电恒温烘箱取出模具，避免高温与身体直接接触造成皮肤灼伤。</li>
	<li>小心地取出霉菌，将聚合的 PMMA 样品 （ZGO： Mn-PMMA） 暴露在紫外线灯下约 3 分钟。例如，当通过字母 H 形状的黑色纸板切口将透明的 ZGO：Mn-PMMA 薄膜暴露在紫外线下时，会获得相应的绿色磷光发射图案。图案可在 5 分钟后擦除。随后，可以通过使用另一个不同字母形状的黑色纸板剪纸来重复该过程，生成新的发光图案。</li>
</ol>

持久性发光纳米颗粒的水热合成

没有什么可披露的。

本文介绍了一种用于持久性发光纳米材料的合成方法和用于显色应用的聚合。这些材料在停止紫外线激发后表现出极其稳定的光学性能和可见的余辉。使用具有不同 pH 值的水热法制备持久性发光纳米材料 （Zn2GeO4： Mn） （图 1A）。TEM 图像显示 pH 值为 9.4 的 ZGO：Mn PLNP 为棒状，平均直径约为 65 nm（图 1B）。高分辨率 TEM 图像显示纳米材?...

持续发光 （PL） 是一种独特的光学过程，它可以储存来自紫外线、可见光、X 射线或其他激发源的能量，然后以光子发射的形式释放几秒钟、几分钟、几小时甚至第1 天。连续发光现象的发现起源于 1000 年前的中国古代宋朝，当时一位画家无意中发现了一幅在黑暗中发光的画作。后来发现，一些天然原料和矿物质可以吸收阳光，然后在黑暗中发光，甚至可以制成迷人的发光珍珠2。然而，持久性荧光粉的第一个充分记录需要追溯到 17世纪初从博洛尼亚石中发现的 PL 发射，它在黑暗中发出黄色到橙色的余辉 1,2,3,4。后来发现 BaS 中 Cu+ 的天然杂质在这种持续发光现象中起了重要作用 1,4。直到 1990 年代中期，持久性荧光粉的生产主要限于硫化物5。1996 年，Matsuzawa 等人报道了一种新的金属氧化物 （SrAl2O4：Eu2+， Dy3+） 荧光粉，显示出极亮的余辉，这极大地刺激了持续发光研究的扩展6。
持久发光材料的独特性能主要来自两种活性中心：发射中心和陷阱中心 1,7,8。其中，前者决定发射波长，而持续强度和时间主要由陷阱中心决定。因此，PL 材料的设计应同时考虑这两个方面，以实现所需的发射波长和持久的发光 9,10。发射中心可以是具有 5d 到 4f 或 4f 到 4f 跃迁的镧系离子、具有 d 到 d 跃迁的过渡金属离子，或具有 p 到 s 跃迁 1,11,12,13 的后过渡金属离子。另一方面，陷阱中心是由晶格缺陷或各种共掺杂剂14,15 形成的，它们通常不发射辐射，而是将激发能量储存一段时间，然后通过热或其他物理激活逐渐将其释放到发射中心16,17。已经报道了许多具有不同主体和掺杂剂离子的荧光粉。到目前为止，已发现无机金属化合物18、金属有机框架8、某些有机复合材料19 和聚合物20 具有 PL 特性。近年来，具有可控储能和光子释放特性的深阱持久发光材料在信息存储21、多层防伪22 和先进显示器23 中显示出巨大的潜在应用前景。
基于上述组成，已成功设计合成了各种基质的 PLNP，如 BaZrSi3O97、Y2O2S24、Ca14Mg2（SiO4）825、CaAl2O426、SrAl2O426,27 和 Sr2MgSi2O728具有多掺杂发光中心，其中发光中心强烈依赖于主晶格的晶场效应，而不同掺杂产生或改善的缺陷作为控制余辉强度和持续时间的辅助中心。除了共掺杂之外，在仅使用一种激活剂的情况下还可以观察到持久的发射，例如具有 Y3Al2Ga3O1229、BaGa2O430、Ca2SnO431、CdSiO332 和 Zn3Ga2Ge2O10 33 基体的异质 PLNP。锗酸盐基三元氧化物包括 Ca2Ge7O16、Zn2GeO4、BaGe4O9 等，是典型的宽带隙半导体材料，具有可调谐发射、发光可重现和稳定、量子产率高、环境友好和广泛可用 34,35,36.这些优点使其成为一种良好的活化剂型光致发光载体。在过去的几年中，通过常规的固态反应或化学溶液方法制备了具有各种微观结构35,37 的锗酸盐，这些特性使 Zn2GeO4 可用于灭菌38、防伪39、催化40、发光二极管41、生物传感42、电池阳极43、探测器44,45 等。
为了扩大 PL 材料的应用，人们开发了均匀和持久的发光纳米颗粒的可控合成。十年前，持久性荧光粉是通过固态合成的46。然而，合成过程中反应时间长、退火温度高，导致荧光粉大且不规则，限制了它们在生物医学等其他领域的应用。2007 年，Chermont 等人首次采用溶胶-凝胶法合成纳米颗粒，制备了 Ca0.2Zn0.9Mg0.9Si2O6：Eu2+、Dy3+、Mn2+，开启了 PLNPs47 的时代。然而，自上而下的合成策略伴随着大小和形态不可控等问题，因此研究人员在开发可控的自下而上合成 PLNPs 方面做了大量工作。2015年以来，各种合成方法相继出现，如模板合成法、水热/溶剂热法、溶胶-凝胶法等湿法化学合成方法，用于合成均匀可控的PLNPs47、48、49、50。其中，水热合成是制备纳米材料最常用的方法之一，可提供一种可调节且温和的合成方法来制备具有特殊结构和性能的化合物或材料51。
在这里，我们提出了一个详细的实验程序，通过水热法合成具有 1D 纳米棒形态的 Zn2GeO4：Mn PLNPs，并为它们提供刚性环境以用于进一步的照明应用。研究发现，通过调节前驱体的 pH 值，可以改变 PLNPs 的发光特性，包括发射波长和余辉衰减曲线。另一方面，为了强调该方法的多功能性，我们还以 ZnGa2O4 为基体 （ZnGa2O4： Cr） 合成了以 Cr 为发光中心的 PLNPs，它在被紫外线 （365 nm） 激发后在近红外区域表现出余辉发射 （697 nm）。本文主要关注前驱体溶液 pH 值为 9.4 的 Zn2GeO4：Mn，用于二维和三维艺术品的制作和可视化。Zn2GeO4：Mn 是一种以 Mn 离子为发光中心的纳米材料，在 365 nm 紫外光激发下获得强烈的绿光发射 （~ 537 nm）。同时，停止励磁后仍能看到持续的绿灯。为了促进 PLNPs 在甲基丙烯酸甲酯中的聚合，在水热合成过程中加入配体（聚乙二醇），然后将 PLNPs 与甲基丙烯酸甲酯 （MMA） 在二维或三维模具中聚合，使其在顺利脱模的同时形成发光的艺术品。
该协议为 PLNP 在高级显色中的水热合成、聚合反应和发光应用提供了一种可行的方法。纳米晶体生长过程中 pH 值、温度和化学试剂的任何差异都会影响 PLNP 纳米结构的尺寸和光学特性。该详细协议旨在帮助该领域的新研究人员使用水热方法提高 PLNP 的可重复性，以实现更广泛的应用。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>azobisisobutyronitrile (99%)</td>
			<td>Macklin</td>
			<td>A800354</td>
			<td>Further purification required</td>
		</tr>
		<tr>
			<td>methyl methacrylate(99%)</td>
			<td>Sigma-Aldrich</td>
			<td>M55909</td>
			<td>Further purification required</td>
		</tr>
		<tr>
			<td>deionized water</td>
			<td>Merck</td>
			<td>ZEQ7016T0C</td>
			<td>Milli-Q&#160;Direct Water Purification System</td>
		</tr>
		<tr>
			<td>alkaline aluminum oxide (100-200 mesh)</td>
			<td>Macklin</td>
			<td>A800033</td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;ammonium hydroxide&#160; (25%-28%, wt)</td>
			<td>Macklin</td>
			<td>A801005</td>
			<td></td>
		</tr>
		<tr>
			<td>beaker&#160;</td>
			<td>Synthware</td>
			<td>B220100</td>
			<td></td>
		</tr>
		<tr>
			<td>chromium(III) nitrate nonahydrate (99.95%)</td>
			<td>Aladdin</td>
			<td>C116448</td>
			<td></td>
		</tr>
		<tr>
			<td>centrifuge</td>
			<td>ThermoFisher Scientific</td>
			<td>75004250</td>
			<td></td>
		</tr>
		<tr>
			<td>column</td>
			<td>Synthware</td>
			<td>C184464CR</td>
			<td></td>
		</tr>
		<tr>
			<td>digital camera</td>
			<td>&#160;Canon</td>
			<td>EOS M50 Mark II</td>
			<td></td>
		</tr>
		<tr>
			<td>electric thermostaticdrying oven</td>
			<td>Longyue</td>
			<td>LDO-9036A</td>
			<td></td>
		</tr>
		<tr>
			<td>ethanol (99.7%)</td>
			<td>Greagent</td>
			<td>1158566</td>
			<td></td>
		</tr>
		<tr>
			<td>gallium nitrate hydrate(99.9%)</td>
			<td>Aladdin</td>
			<td>G109501</td>
			<td></td>
		</tr>
		<tr>
			<td>germanium oxide (99.99%)</td>
			<td>Sinopharm Chemical ReagentCo., Ltd</td>
			<td>51009860</td>
			<td></td>
		</tr>
		<tr>
			<td>glass rod</td>
			<td>Sinopharm Chemical ReagentCo., Ltd</td>
			<td>91229401</td>
			<td></td>
		</tr>
		<tr>
			<td>powder X-Ray Diffractometer</td>
			<td>D2 PHASER DESKTOP XRD</td>
			<td>BRUKER</td>
			<td></td>
		</tr>
		<tr>
			<td>manganese nitrate (98%)</td>
			<td>Macklin</td>
			<td>M828399</td>
			<td></td>
		</tr>
		<tr>
			<td>methanol (99.5%)</td>
			<td>Greagent</td>
			<td>1226426</td>
			<td></td>
		</tr>
		<tr>
			<td>nitric acid (65.0-68.0%, wt)</td>
			<td>Sinopharm Chemical ReagentCo., Ltd</td>
			<td>10014508</td>
			<td></td>
		</tr>
		<tr>
			<td>pH meter</td>
			<td>Shanghai Leici Sensor Technology Co., Ltd</td>
			<td>PHS-3C</td>
			<td></td>
		</tr>
		<tr>
			<td>polyethylene glycol (300, Mw)</td>
			<td>Adamas</td>
			<td>01050882(41713A)</td>
			<td></td>
		</tr>
		<tr>
			<td>sealing film</td>
			<td>Parafilm</td>
			<td>2025722</td>
			<td></td>
		</tr>
		<tr>
			<td>sodium hydroxide (GR)</td>
			<td>Sinopharm Chemical ReagentCo., Ltd</td>
			<td>10019764</td>
			<td></td>
		</tr>
		<tr>
			<td>spectrometer</td>
			<td>Horiba</td>
			<td>Fluorolog-3&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>transmission electron microscope</td>
			<td>JEOL&#160;</td>
			<td>JEM-1400 Plus</td>
			<td></td>
		</tr>
		<tr>
			<td>transmission electron microscope</td>
			<td>JEOL</td>
			<td>2100 Plus&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>triangular funnel</td>
			<td>Synthware</td>
			<td>F181975</td>
			<td></td>
		</tr>
		<tr>
			<td>ultrasound machine</td>
			<td>centrifuge</td>
			<td>JP-040S</td>
			<td></td>
		</tr>
		<tr>
			<td>zinc chloride (98%)</td>
			<td>Greagent</td>
			<td>01113266/G81783A</td>
			<td></td>
		</tr>
	</tbody>
</table>

synthesis of persistent luminescent nanoparticles for rewritable displays and illumination applications

持续发光纳米颗粒 （PLNP） 具有即使在激发停止后也能保持延长寿命和稳健发射的能力。PLNP 已广泛应用于各个领域，包括信息显示、数据加密、生物成像和艺术装饰，具有持续生动的亮度，为各种创新技术和艺术项目提供了无限可能。该协议侧重于 PLNP 的水热合成的实验程序。以 Mn2+ 或 Cr3+ 作为 Zn2GeO4：Mn （ZGO： Mn） 或 ZnGa2O4： Cr 的发光中心的成功合成了持久发光纳米材料，突出了这种合成方法的普遍性。另一方面，ZGO：Mn 的光学特性可以通过调节前驱体溶液的 pH 值来改变，证明了该方案的可调性。当用 365 nm 波长的紫外线 （UV） 充电 3 分钟然后停止时，PLNP 表现出高效、一致地产生余辉的非凡能力，这使其成为制作二维可擦写显示器和三维透明、发光艺术品的理想选择。本文概述的该协议为合成持久性发光纳米颗粒提供了一种可行的方法，用于进一步的照明和成像应用，为科学和艺术领域开辟了新的前景。

Persistent luminescence (PL) is a unique optical process that can store energy from ultraviolet light, visible light, X-rays, or other excitation sources and then release it in the form of photon emission for seconds, minutes, hours, or even for days1. The discovery of continuous luminous phenomenon originated from the Song dynasty in ancient China 1000 years ago when a painter accidentally discovered a painting that glowed in the dark. It was later found that some natural raw materials and minerals could absorb sunlight and then glow in the dark and can even be made into fascinating glowing pearls2. However, the first adequate record of persistent phosphors needed to be traced back to the discovery of PL emission from Bologna stone in the early 17th century, which gave off a yellow to orange afterglow in the dark1,2,3,4. Later, it was discovered that the natural impurities of Cu+ in BaS played an important role in this persistent luminescence phenomenon1,4. Until the mid-1990s, the production of persistent phosphors was largely limited to sulfides5. In 1996, Matsuzawa et al. reported a new metal oxide (SrAl2O4:Eu2+, Dy3+) phosphor showing extremely bright afterglow, which greatly stimulated the expansion of persistent luminescence research6.
The unique properties of persistent luminescent materials are mainly derived from two kinds of active centers: emission centers and trap centers1,7,8. Among them, the former determines the emission wavelength, while the sustained intensity and time are mainly determined by the trap centers. Therefore, the design of PL materials should take both aspects into consideration in order to achieve the desired emission wavelength and long-lasting luminescence9,10. The emission centers can be lanthanide ions with 5d to 4f or 4f to 4f transitions, transition metal ions with d to d transitions, or post-transition metal ions with p to s transitions1,11,12,13. On the other hand, trap centers are formed by lattice defects or various co-dopants14,15, which usually do not emit radiation but instead store the excitation energy for a while and then gradually release it to the emitting center through thermal or other physical activation16,17. Many phosphors with different hosts and dopant ions have been reported. So far, inorganic metal compounds18, metal-organic frameworks8, certain organic composites19, and polymers20 have been found to have PL properties. In recent years, deep trap persistent luminescent materials with controllable energy storage and photon release properties have shown great potential applications in information storage21, multi-layer anti-counterfeiting22, and advanced displays23.
Based on the above composition, PLNPs with various matrices have been successfully designed and synthesized, such as BaZrSi3O97, Y2O2S24, Ca14Mg2(SiO4)825, CaAl2O426, SrAl2O426,27 , and Sr2MgSi2O728 with multi-doped luminescent centers, in which the luminescence centers strongly depend on the crystal field effect of the host lattice, while the defects generated or improved by different doping serve as auxiliary centers to control the afterglow intensity and duration. In addition to co-doping, long-lasting emission can also be observed in the case of only one activator, such as heterogeneous PLNPs with the matrix of Y3Al2Ga3O1229, BaGa2O430, Ca2SnO431, CdSiO332 , and Zn3Ga2Ge2O1033. Germanate-based ternary oxides include Ca2Ge7O16, Zn2GeO4, BaGe4O9, etc., which are typical wide-bandgap semiconductor materials with tunable emission, reproducible and stable luminescence, high quantum yield, environmental friendliness and wide availability34,35,36. These advantages make it a good activator-type photoluminescent carrier. In the past few years, germanates with various microstructures35,37, have been prepared by conventional solid-state reactions or chemical solution methods, and these characteristics make Zn2GeO4 useful in sterilize38, anti-counterfeiting39, catalysis40, light diodes41 , biosensing42, battery anodes43, detectors44,45, etc.
In order to expand the application of PL materials, the controllable synthesis of uniform and persistent luminescent nanoparticles has been developed. A decade ago, persistent phosphors were synthesized by solid-state synthesis46. However, the long reaction time and high annealing temperature during the synthesis process resulted in large and irregular phosphors, which limited their application in other fields such as biomedicine. In 2007, Chermont et al. used sol-gel approach to synthesize nanoparticles for the first time and prepared Ca0.2Zn0.9Mg0.9Si2O6: Eu2+, Dy3+, Mn2+, which opened the era of PLNPs47. However, the top-down synthesis strategy is accompanied by problems such as uncontrollable size and morphology, so researchers have done a lot of work in the development of controllable bottom-up synthesis of PLNPs. Since 2015, various synthesis methods have emerged one after another, such as the template synthesis method, hydrothermal/solvent thermal method, sol-gel method and other wet chemical synthesis methods for the synthesis of uniform and controllable PLNPs47,48,49,50. Among them, hydrothermal synthesis is one of the most commonly used methods for preparing nanomaterials, which can provide an adjustable and mild synthetic method to prepare compounds or materials with special structures and properties51.
Here, we present a detailed experimental procedure for synthesizing Zn2GeO4: Mn PLNPs with 1D nanorods morphology via the hydrothermal method and providing them with a rigid environment for further illumination applications. It was found that the luminescence properties of PLNPs, including emission wavelength and afterglow decay curve, can be changed by adjusting the pH value of the precursor. On the other hand, to emphasize the versatility of this method, we also synthesize PLNPs with Cr as the luminescent center using ZnGa2O4 as the matrix (ZnGa2O4: Cr), which exhibits afterglow emission (697 nm) in the near-infrared region after being excited by ultraviolet light (365 nm). This article mainly focuses on Zn2GeO4: Mn whose pH value of precursor solution is 9.4 for two-dimensional and three-dimensional artworks production and visualization. Zn2GeO4: Mn is a type of nanomaterial with Mn ions as the luminescent center which obtains strong green light emission (~ 537 nm) under the excitation of 365 nm ultraviolet light. At the same time, the continuous green light can still be seen after stopping excitation. In order to promote the polymerization of PLNPs in methyl methacrylate, ligands (Poly-ethylene glycol) were added during the hydrothermal synthesis process, and then PLNPs were polymerized with methyl methacrylate (MMA) in a two-dimensional or three-dimensional mold so that it can form glowing artwork while smoothly demolding.
This protocol provides a feasible method for the hydrothermal synthesis, polymerization reactions, and luminescent applications of PLNPs in advanced color rendering. Any differences in pH, temperature, and chemical reagents during nanocrystal growth will affect the size and optical properties of PLNP nanostructures. This detailed protocol aims to help new researchers in the field to improve the reproducibility of PLNPs using a hydrothermal method for further wider applications.

作者聚焦：利用功能纳米材料推进生物成像和治疗

用于可擦写显示器和照明应用的持久性发光纳米颗粒的合成

Our research focuses on developing functional nanomaterials based on precise biotechnology. We aim to achieve bioimaging disease treatment, and physiological function regulation in a minimally invasive and highly selective fashion by using nano composites with luminescence, thermal magnetic, and acoustic properties. We have demonstrated that utilizing a rigid backbone chain polymer, polymethyl methacrylate as the matrix, purely polycyclic aromatic hydrocarbons can exhibit stable and exceptionally long phosphorescent lifetimes, showcasing purely organic room temperature phosphorescent properties.We expect that this protocol not only provide a detailed experimental procedure for the hydrothermal synthesis of long-lasting imaging nanomaterials, but also introduce the method for the copolymerization of persistent luminescent nanoparticles and MMA to further achieve ultraviolet mediated rewriteable and luminescent applications. The hydrothermal synthesis masses of persistent luminescent nanoparticles could restrict the application of certain temperature sensitive substance since they require relatively high reaction temperatures. Consequently, the selection of an appropriate synthesis method should be contingent on specific application and requirement.The main research directions in our laboratory include the development of temperature-sensitive luminescence nanoprobe for microscopic temperature monitoring, immune cells selective nanocomposite for immune imaging and therapy, and the establishment of new acoustic and magnetic responsive materials.

Zn2GeO4：Mn （ZGO： Mn） PLNPs 的合成图如图 1 所示。添加两亲性聚合物聚乙二醇 （PEG） 以修饰无配体的 Zn2GeO4：Mn （ZGO： Mn） 纳米棒，以更好地溶解在 MMA 介质中。首先，收集 pH 值为 9.4 的 ZGO：Mn 的透射电子显微镜 （TEM）、高分辨率透射电子显微镜 （HRTEM） 图像（图 1），然后进行动态光散射 （DLS）、zeta 电位结果和 ZG...

提出了一种用于合成持续发光纳米材料 （PLNP） 的方案，以及它们在紫外线 （365 nm） 照射下利用余辉效应在可擦写显示器和艺术加工中的潜在应用。

Persistent luminescent nanoparticles (PLNPs) possess the capabilities to maintain extended longevity and robust emission even after the excitation has ...

我们的研究重点是开发基于精确生物技术的功能性纳米材料。我们的目标是通过使用具有发光、热磁和声学特性的纳米复合材料，以微创和高选择性的方式实现生物成像疾病治疗和生理功能调节。我们已经证明，利用刚性主链聚合物聚甲基丙烯酸甲酯作为基质，纯多环芳烃可以表现出稳定且超长的磷光寿命，表现出纯有机室温磷光特性。我们期望该协议不仅为长效成像纳米材料的水热合成提供详细的实验程序，而且还介绍了持久性发光纳米颗粒和 MMA 共聚的方法，以进一步实现紫外线介导的可重写和发光应用。持久性发光纳米颗粒的水热合成质量可能会限制某些温度敏感物质的应用，因为它们需要相对较高的反应温度。因此，选择合适的合成方法应取决于具体的应用和要求。本实验室的主要研究方向包括开发用于显微温度监测的温敏发光纳米探针、用于免疫成像和治疗的免疫细胞选择性纳米复合材料，以及新型声磁响应材料的建立。

synthesis-persistent-luminescent-nanoparticles-for-rewritable

Research

JoVE Journal

Chemistry

Synthesis of Persistent Luminescent Nanoparticles for Rewritable Displays and Illumination Applications

957 次观看.  Shanghai Tech University. 我们的研究重点是开发基于精确生物技术的功能性纳米材料。我们的目标是通过使用具有发光、热磁和声学特性的纳米复合材料，以微创和高选择性的方式实现生物成像疾病治疗和生理功能调节。我们已经证明，利用刚性主链聚合物聚甲基丙烯酸甲酯作为基质，纯多环芳烃可以表现出稳定且超长的磷光寿命，表现出纯有机室温磷光特性。我们期望该协议不仅为长效成像?...

视频: 作者聚焦：利用功能纳米材料推进生物成像和治疗

Persistent luminescent nanoparticles (PLNPs) possess the capabilities to maintain extended longevity and robust emission even after the excitation has ceased. PLNPs have been widely used across various domains, including information displays, data encryption, biological imaging, and artistic decoration with sustained and vivid luminosity, providing boundless possibilities for a variety of innovative technology and artistic projects. This protocol focuses on an experimental procedure for the hydrothermal synthesis of PLNPs. The successful synthesis of enduring luminescent nanomaterials with Mn2+ or Cr3+ serving as a luminescent center in Zn2GeO4: Mn (ZGO: Mn) or ZnGa2O4: Cr highlights the universality of this synthetic method. On the other hand, the optical properties of ZGO: Mn can be changed by adjusting the pH of precursor solutions, demonstrating the tunability of the protocol. When charged with ultraviolet (UV) at a wavelength of 365 nm for 3 min and then stopped, PLNPs exhibit the remarkable capacity to generate afterglow efficiently and consistently, which makes them ideal for making two-dimensional rewritable displays and three-dimensional transparent, luminous artworks. This protocol outlined in this paper provides a feasible method for the synthesis of persistent luminescent nanoparticles for further illumination and imaging applications, opening up novel prospects for the fields of science and art.

A protocol is presented for the synthesis of persistent luminescent nanomaterials (PLNPs) and their potential applications in rewritable displays and artistic processing utilizing the afterglow effect under ultraviolet light (365 nm) irradiation.

科研

化学

Synthesis of Zn2GeO4&#58; Mn Persistent Luminescent Nanoparticles (PLNPs)

To begin, take five milliliters of deionized water and add 10 millimolars of sodium hydroxide to it. Then add two millimolars of germanium oxide to the sodium hydroxide solution to prepare sodium germinate solution and stir the mixture at room temperature for about 30 minutes. Next, add four millimolars of zinc chloride, 0.01 millimolars of manganese nitrate, and 600 microliters of nitric acid to 22 milliliters of deionized water and stir until completely dissolved.Now, slowly add the sodium germinate solution to the prepared solution and add one milliliter of polyethylene glycol. Then place the calibrated pH meter probe into the solution to monitor the pH value. Add ammonium hydroxide with a mass fraction of 25 to 28%to the solution drop by drop and adjust the pH to 6.0, 8.0, or 9.4.Cover the beaker with sealing film, and stir the solution at room temperature for one hour while maintaining a constant stirring speed. Afterward, transfer the solution to a Teflon lined autoclave and place it in an electric thermostatic drying oven at 220 degrees Celsius for four hours. After completion, turn off the oven and let the system cool to room temperature before taking out the reactor.Open the reactor slowly and transfer the reaction solution to 250 milliliter centrifuge tubes. Rinse the reactor with 40 milliliters of ethanol and transfer the ethanol to the tubes. Then vortex the solution for 30 seconds.Centrifuge at 4, 000 G for 15 minutes at room temperature and remove the supernatant. Next, add 10 milliliters of deionized water to each tube and sonicate for five minutes to redisperse the product. Add 20 milliliters of ethanol to each tube and vortex for 30 seconds for even mixing.Repeat the centrifugation process and discard the supernatant. Ultrasonicate the product for five minutes to disperse the product in two milliliters of methanol solution and store the sample at four degrees Celsius after sealing it with sealing film. The TEM image showed that zinc germinate manganese PLNPs with pH 9.4 were rod shaped and had an average diameter of about 65 nanometers.The high resolution TEM images demonstrated that the nanomaterials had good crystallinity with a lattice spacing of 0.70 nanometers. The afterglow visible emission spectra of the zinc germinate manganese solution showed that the PLNPs exhibited a red shift of the main emission peak when the precursor solution changed from acidic to alkaline. Additionally, the pH value had an impact on the decay curve of afterglow intensity over time.The photo luminescence images and afterglow images of PLNPs revealed that the solution exhibited a brighter green luminescence as the alkalinity of the solution increased.

Zn2GeO4 的合成：Mn 持续发光纳米颗粒 （PLNP）

Copolymerization of Methyl Methacrylate (MMA) and Zn2GeO4&#58; Mn Persistent Luminescent Nanoparticles

To begin, set the water bath temperature to 80 degrees Celsius. Add 20 grams of MMA into a dry 100 milliliter eggplant shaped bottle. Add the pre-prepared methanol solution of zinc germinate manganese with pH 9.4 into the reaction vessel.Seal the reaction vessel to prevent solvent evaporation. Place the vessel in an ultrasonicator for about 10 minutes at room temperature to dissolve the sample in MMA. Next, add 0.012 grams of Azobisisobutyronitrile to the solution and mix completely.Place the flask in an 80 degree Celsius water bath and purge air with nitrogen for approximately 35 minutes. Gently shake the container towards the end of the reaction. Quickly transfer the reaction vessel to an ice bath to cool it down after the reaction.Then slowly pour the solution into a two dimensional or three dimensional mold. Place the mold in an electric thermostatic drying oven set at specific temperatures to obtain the target material. Afterward, close the electric thermostatic drying oven once the reaction stops, allowing it to cool to room temperature.Open the oven to remove the mold only after it has sufficiently cooled to prevent skin burns. Carefully demold the polymerized PMMA sample and expose it to a UV lamp for approximately three minutes.